Ballistics

FIREARMS IDENTIFICATION AND INVESTIGATION INTRODUCTION Ballistics (gr. ba'llein, "throw") is the science that deals with the motion, behavior, and effects of projectiles, especially bullets, gravity bombs, rockets, or the like; the science or art of designing and hurling projectiles so as to achieve a desired performance. A ballistic body is a body which is free to move, behave, and be modified in appearance, contour, or texture by ambient conditions, substances, or forces, as by the pressure of gases in a gun, by rifling in a barrel, by gravity, by temperature, or by air particles. Firearm ballistics information is used in forensic science. Separately from ballistics information, firearm and tool mark examinations involve analyzing firearm, ammunition, and tool mark evidence in order to establish whether a certain firearm or tool was used in the commission of a crime. Ballistics is sometimes subdivided into: 1. 2. 3. 4.

Internal ballistics, the study of the processes originally accelerating the projectile, for example the passage of a bullet through the barrel of a rifle; Transition ballistics, the study of the projectile's behavior when it leaves the barrel and the pressure behind the projectile is equalized. External ballistics, the study of the passage of the projectile through space or the air; and Terminal ballistics, the study of the interaction of a projectile with its target, whether that be flesh (for a hunting bullet), steel (for an anti-tank round), or even furnace slag (for an industrial slag disruptor).

“Ballista” is a gigantic bow or catapult which was used to hurl large objects such as stones at a particular distance to deter animals or enemy forces. Today, the word Ballistics is frequently used synonymously in the press and in the Police Parlance to Firearms Identification. BALLISTICS It is a science in itself because it evolved from systematic knowledge, research and development, training, experience and education of those who pioneered in this field. Technically speaking, it refers to the "science of firearms identification which involves the scientific examination of ballistics exhibits such as: fired bullets; fired shells; firearms; and allied matters, used in crime. Legally speaking, ballistics is the microscopic examination of fired cartridge cases and bullets together with the recording and presentation by means of photography of what is revealed by the microscope. BALLISTICS THEORY Ballistics is the scientific study of the propulsion and motion of projectiles such as bullets, artillery shells, rockets and guided missiles. Also includes the study of the destructive action of such projectiles. The drag of a projectile moving head on is now usually divided into three parts: 1. 2. 3.

bow resistance - due to air pressure at the head of the projectile; skin friction - caused by the friction of air moving along the middle portion of the body; and base drag - due to the under-pressure and disturbance of the air behind the base. The following are pioneers in the study of force and projectiles:

1. 2. 3.

GALILEO, NEWTON, and LEIBNIZ established the principles of dynamics and the methods of calculus, studies which helped the rapid development of external ballistics. GALILEO and NEWTON were both interested in the force called air resistance, now usually called aerodynamic drag, which reduces the speed of a projectile. In 1707, CASSINI, an astronomer suggested measuring firearm’s muzzle velocity.

INTERIOR BALLISTICS It is the study of motion of projectiles within the gun barrel. The time during which the projectile is influenced by Interior Ballistics is very short. From the release of the firing pin to the moment the sound of the shot can be heard as it leaves the muzzle occupies only about 0.01 seconds, in a modern rifle. Interior ballistics involves: 1. 2. 3. 4. 5. 6. 7. 8.

Ignition of the primer. Flames is produced Combustion of the gunpowder Energy that is generated Force/Pressure developed Velocity of the bullet (from the chamber to the muzzle) Rotation of the bullet Engraving of the cylindrical surface of the bullet.

Interior ballistics deals with the temperature, volume, and pressure of the gases resulting from combustion of the propellant charge in the gun; it also deals with the work performed by the expansion of these gases on the gun, its carriage, and the projectile. Some of the critical elements involved in the study of interior ballistics are the relationship of the weight of charge to the weight of projectile; the length of bore; the optimum size, shape, and density of the propellant grains for different guns; and the related problems of maximum and minimum muzzle pressures. Note the following: The British engineer Benjamin Robins conducted many experiments in interior ballistics. His findings justly entitle him to be called the father of modern gunnery. Late in the 18th century the Anglo-American physicist Benjamin Thompson made the first attempt to measure the pressure generated by gunpowder. The account of his experiments was the most important contribution to interior ballistics that had been made up to that time. About 1760 French ballisticians determined the relationship of muzzle velocity to length of barrel by measuring the velocity of a musket ball and cutting off a portion of the barrel before taking the velocity of the next shot. By using the results of these experiments and advances in chemistry and thermodynamics, ballisticians developed formulas showing the relationship between muzzle velocity and weight and shape of projectile; weight, type, and grain size of powder charge; pressure and temperature in the barrel; and the size of the powder chamber and the length of the barrel. Related Terms in Interior Ballistics 1. 2.

3.

Action – term referring to the mechanism of a firearm. Burning Rate - An arbitrary index of the quickness that burning propellant changes into gas. Burning rate is controlled by the chemical composition, the size and shape of the propellant grains, and the pressure at which the burning takes place. IMR 5010 powder is very slow burning and Bulls eye is fast burning. Bulk Density - The ratio of the weight of a given volume of powder vs. the weight of the same volume of water.

4. 5.

Chamber Pressure – the pressure generated within the chamber erroneously called breeched pressure. Charge Weight to Bullet Weight ratio - This is the ratio of the weight of the powder charge to the weight of the projectile.

6.

Detonation – Chemical rearrangement of molecules into gas instead of solids to cause the high explosives to exert full power of shock. The speed of detonation varies in different explosive but in some it is as high as 7000 yards in a second. Energy - is measured in foot-pounds, and one foot-pound means that amount of energy, which would be capable of lifting a weight of one pound through a distance of one foot Drop-Block Action- That type of action in which the breechblock rises and forces vertically in cuts in the receiver side walls. Lever actuated as a rule. Expansion Ratio - The ratio of the capacity of the powder chamber plus bore (in grains of water) to the capacity of the powder chamber (in grains of water).

7. 8.

9. 10. 11.

Foot – Pound - the amount of work required to raise one pound one foot high against the force of gravity. Foot second - velocity expressed in foot per second. Gas - a fluid resulting from the combustion of gun powder with a relatively great expansion and spontaneous tendency. 12. Hangfire - Occurs when a cartridge fails to explode on time or delayed in firing. 13. Knocking Power - the power of the bullet which delivers a very heavy paralyzing blow that put the victim down and may then recover if the wound inflicted upon is not fatal. 14. Loading Density - The ratio of the weight of the powder charge to the capacity of the powder chamber (case). It is usually expressed as the ratio of the charge weight to the capacity the powder chamber in grains of water. (See below.) Generally, the more fully the powder charge fills the case the more consistent and accurate the load will be. On the other hand if the loading density is too low, (too much free space in the case) it can cause erratic ignition, change in the pressure curve (moving the peak towards the muzzle), or even overly rapid burning ("detonation") of the powder charge. (One reason manuals list minimum or starting loads.) 15.

Misfire – total failure of a cartridge to discharge. This is different from hang fire which merely a delayed combustion, while misfire a complete failure eve to start combustion. 16. Powder Chamber Capacity - As with most interior ballistics capacity measurements it is usually expressed in grains of water. It is determined by measuring the weight of water that a fired case from the test firearm can contain with a bullet seated to its normal depth. Note that this varies with different bullets or seating depth as well as the dimensions of the chamber, and the brand of case. 17. 18. 19.

Pressure – Outward push of gases from powder combustion against cartridge case, chamber and bore. Sectional Density - The ratio of the bullet's weight (in pounds) to its diameter. PSI - Pounds per square inch. It is often seen designated as PSIA. This designation is now used to signify a measurement of chamber pressure taken with a piezo-electric device. Piezo-electric units operate in a similar fashion to the copper crusher units but use a reusable crystal "crusher" that changes its electrical properties in response to pressure. When connected to suitable recording equipment the entire pressure pulse history can be recorded or displayed. The peak pressure recorded by a piezo-electric peak device usually reads about 5,000 psi higher than the figure determined by the copper crusher method.

20.

Recoil – the equal and opposite reaction of the gun against the forward movement of the bullet during the explosions. 21. Residual Pressure – the pressure remaining in the chamber after the bullet has left the barrel. EXTERIOR BALLISTICS Exterior Ballistics deals with the motion of projectiles from the time they leave the muzzle of the firearm to the time they hit the target. The flight of most bullet or projectile does not exceed 30 seconds at maximum range, which for almost any firearms is obtained at an elevation of about 33.

CONDITIONS - refers to the natural laws. a. velocity - speed per unit of time ex. M16 - 3,300 ft/sec. b. energy - fatal equivalent of a bullet. c. yaw - the unstable rotating motion of a bullet. d. gyroscopic action - refers to the stillness of its rotating motion and attained its highest momentum or stability in flight and penetrating power. In exterior ballistics, elements such as shape, caliber, weight, initial velocities, rotation, air resistance, and gravity help determine the path of a projectile from the time it leaves the gun until it reaches the target. Until the middle of the 16th century it was believed that bullets move in straight lines from the gun to the target and that shells fired from mortars describe a path made up of two straight lines joined by an arc of a circle. The Italian mathematician Niccolò Tartaglia, in a published work on gunnery, claimed that no part of the path of a projectile could be a straight line and that the greater the velocity of the projectile the flatter its path. Tartaglia invented the gunner's quadrant used to determine elevation of the muzzle of a gun. He is and Italian scientist who a book in which he said that the trajectory of a bullet was really a continuous curve. He directed some firing tests to determine this angle, and discovered that it was near 45 degrees and he noted that the trajectory was continuously curve. Galileo proved that in a vacuum a projectile describes a parabolic arc. The description of the law of gravitation by the British scientist Sir Isaac Newton made plain the cause of the curvilinear motion of projectiles. By the use of calculus he determined the momentum transferred from the projectile to the particles of air at rest; this method of calculating air drag has been superseded by the use of tables prepared from experimental firings. Two methods have been used to determine the velocity of a projectile after it leaves the gun. One method measures the momentum of the projectile; the other measures the time required for the projectile to travel a given distance. The first method is the older, and in the past, when guns and projectiles were small, velocities low, and ranges short, the results were sufficiently accurate for most practical purposes. The ballistic pendulum and gun pendulum were used to measure projectile momentum, but these devices have been supplanted by cheaper and more accurate machines working on the principles of the second method. The ballistic pendulum was developed about 1743 by Robins, who was the first to undertake a systematic series of experiments to determine the velocity of projectiles. The principle of the ballistic pendulum, as well as of the gun pendulum, which was developed by Thompson, is the transfer of momentum from a projectile with a small mass and a high velocity to a large mass with a resultant low velocity. The ballistic pendulum consisted of a massive plate of iron to which was bolted a block of wood to receive the impact of the projectile; the pendulum was suspended freely from a horizontal axis. The block, when struck by the projectile, recoiled through a certain arc that was easily measured. Knowing the arc of recoil and the masses of the projectile and the pendulum, the velocity of the projectile could be determined by calculation. The ballistic pendulum was able to withstand the impact of musket balls only; however, by determining the relations that should exist between the caliber, length of barrel, and charge of power, Robins substantially advanced the science of gunnery. By the second method, the velocity of a projectile is determined by measuring the time required for it to travel a known length of its path. Numerous machines have been devised for this purpose; in 1840 the British physicist Sir Charles Wheatstone suggested the use of electricity for measuring small intervals of time. This suggestion led to the development of the chronograph, a device for recording, by electrical means, the time required for a projectile to pass between two screens of fine wire. The formulas and tables for the exterior ballistics of each new type of gun or cannon are more or less empirical and must be tested by actual experiment before the aiming devices can be accurately calibrated. Further, exterior (external) ballistics refers to the attributes and movements of the bullet after it has left the gun muzzle. It includes:

1. 2. 3. 4.

Muzzle blast - the noise created at the muzzle point of the gun due to the sudden escape of the expanding gas coming in contact with the air in the surrounding atmosphere at the muzzle point. Muzzle energy - energy generated at the muzzle point. Trajectory - the actual curved path of the bullet during its flight from the gun muzzle to the target. The following are the kinds of trajectory: straight horizontal line - parabola-like flight - vertical drop Range - the straight distance between the muzzle point and the target. a. Accurate (effective) range - the distance within the shooter has control of his shots, meaning he can place his shots at the desired spots. b. Maximum range - the farthest distance that a projectile can be propelled from a firearm.

* While the range at which the ordinary pistol and revolver are supposed to be effective in only 50-70 yards, all of them can send their bullets much further than that and are capable of inflicting fatal wounds at distances up to one mile, depending on the caliber and gunpowder content. 5.

Velocity - rate of speed of the bullet per unit of time. Long barrel rifle – up to 3,000 yards accurate range and its hinge muzzle velocity of 1000-4000 ft./sec.

* Bullets from rifled weapons spin at 2000-3000 revolutions per second, but over the first few yards of trajectory – distance varies with the weapon – their flight is slightly unstable; the end of the projectile wobbles before it picks up a smooth flight path. This phenomenon is called “TAILWAG”, and is of considerable important in evaluating gunshot wounds. A bullet with “tailwag” does not strike its target clearly. 6. 7. 8.

Air resistance - resistance encountered by the bullet while in flight. Pull of gravity - downward reaction of the bullet while in flight. Penetration - depth of entry on target.

Note on the following Contributors: 1. 2. 3. 4. 5. 6. 7.

8. 9.

1707 - Cassini. Suggested measuring of firearms muzzle velocity 1857 – Monsieur Noiles. Published a thesis titled ‘Les Plaies Feu Courtes’. His thesis dealt with the subject of wounds made by small firearms. 1748 - Henry Shrapnel. He invented the shrapnel, which disperse its load of case shot with a small bursting charge, increasing the effective range of case. 1898 – Mr. Corin in Paris, France. Published an article titled “La Determination de La Distance a’Laguelle un Coup de Feu a e’te’ Tire” (Determination of the distance at which a shot has been discharged from a firearm). 1900 – Dr. Albert Llewellyn Hal in Buffalo, New York (USA). A very significant article entitled “The Missile and the Weapon” was published in the June issue of the Buffalo Medical Journal. 1903 – Mr. E.J. Churchill in London, England (uncle of Robert Churchill of later fame as a firearms examiner for the United Kingdom). He provided testimony as to some experimentation that he had performed involving the distance of which a shot had been fired into a human skull. 1900 - Dr. Albert Llewellyn. He wrote an article entitled “The Missile and the Weapon”, which dealt with a variety of issues to include how measurement of land and groove markings are made on bullets. He also discussed the examination of gunpowder residues in barrels of firearms and the changes that take place over time after the weapon is fired. 1921 - Mr. Jorge T. Filho. He published an article entitled “Estimation of Distance from which a Bullet was Fired” (“Da Diagnose da Distance nos Tiros de Projecteis Multiplos Chumbo de Caca”). Emile Monnin Chamot. He authored a 61-paged monograph entitled “The Microscopy of Small Arms Primers”.

Note on the following Terms in Exterior Ballistics: 1. 2.

Accuracy Range – The maximum distance at which a particular gun and cartridges will consistently place all shots in the standard target for that distance. Accurate Range – The distance within which the shooter has control of his shots.

3.

Back Curve - This is that portion of the bullets trajectory that drops below the critical zone beyond the point blank range. Past this point the trajectory begins to drop off very rapidly with range and the point of impact becomes very difficult to estimate.

4.

Ballistic Coefficient – The means that the bullet may lose its speed very rapidly during its flight the air. This is a number that relates to the effect of air drag on the bullet's flight and which can be used to later predict a bullet's trajectory under different circumstances through what are called "drag tables." Bullet Energy – the power possessed by a moving bullet, or in other words, its ability to keep going when it meets an obstacle and to do work on the obstacle is immense importance, for obviously the more power a bullet has an the harder it is to stop the more effective it can be as a weapon Bullet Trajectory - This is the bullet's path as it travels down range. It is parabolic in shape and because the line of the bore is below the line of sight at the muzzle and angled upward, the bullet's path crosses the line of sight at two locations.

5. 6.

7.

Critical Zone - This is the area of the bullet's path where it neither rises nor falls greater than the dimension specified. Most shooters set this as ± 3" to 4" from the line of sight, although other dimensions are sometimes used. The measurement is usually based on one-half of the vital zone of the usual target. Typical vital zones diameters are often given as: 3" to 4" for small game, and 6" to 8" for big game and anti-personnel use.

8.

Drift - is the curve taken by the bullet while in flight. A right hand rifling curves to the right while that of the left and rifling curves to the left. Effective Range- The maximum distance at which a bullet may reasonably be expected to travel accurately and kill a particular type of live targe Extreme Range – The greatest distance the bullet will travel when the cartridge is fired. Flat Trajectory - A comparative term used to indicate very little curvature in the flight in the bullet from muzzle to point of impact. When the velocity is high, comparatively flat trajectory. Gallery Range - The indoor target range. National rifle association of America, gallery rules required stance from firing point to target of 50 feet or 75 feet for.22 rim fire riffle; 50 feet or 60 feet for .22rim-fire pistols. On properly constructed indoor ranges, firing may be conducted with center fire pistol and revolvers at ranges of 25 yards and 50 yards. Such installation are generally referred to as “indoor range” the term “gallery” being applied usually only to the short range . 22 caliber installation. Gallery Range - The indoor target range. National rifle association of America, gallery rules required stance from firing point to target of 50 feet or 75 feet for.22 rim fire riffle; 50 feet or 60 feet for .22rim-fire pistols. On properly constructed indoor ranges, firing may be conducted with center fire pistol and revolvers at ranges of 25 yards and 50 yards. Such installation are generally referred to as “indoor range” the term “gallery” being applied usually only to the short range . 22 caliber installation. Initial Point - The range at which the bullet's trajectory first crosses the line of sight. This is normally occurs at a range of about 25 yards.

9. 10. 11. 12.

13.

14.

15. Instrument Velocity - the velocity of a projectile measured by the scientific instrument called chronograph, at a specified point on its trajectory. Always lower than the muzzle velocity. 16. Key-hole Shot – the tumbling of the bullet in its flight and hitting the target sideways as a result of not spinning on its axis. 17. Maximum Point Blank Range - This is the farthest distance at which the bullet's path stays within the critical zone. In other words the maximum range at which you don't have to adjust your point of aim to hit the target's vital zone. Unless there is some over riding reason to the contrary shots should not generally be attempted much past this distance. In the words of the Guru, "It is unethical to attempt to take game beyond 300 meters." If you do, you should write yourself a letter explaining why it was necessary to do so. An approximate rule of thumb says that the maximum point blank range is approximately your zero range plus 40 yards. 18. Maximum Range – the farthest distance that a projectile can be propelled from a firearm. 19. Maximum Ordinate - This is the maximum height of the projectile's path above the line of sight for a given point of impact and occurs somewhat past the halfway point to the zero range and it is determined by your zeroing range.

20. Mid-range Trajectory - This is the height of the bullets path above the line of sight at half way to the zero range. It does not occur at the same range as the maximum ordinate height which can be greater. 21. Minute of Angle (MOA) - A "minute" of angle is 1/60 of a degree which for all practical purposes equates to 1 inch per 100 yards of range. Thus 1 MOA at 100 yards is 1 inch and at 300 yards it is 3 inches. The term is commonly used to express the accuracy potential of a firearm. 22. Point Blank Range – Popularly used to indicate the distance the bullet will travel before it drops enough to require sight adjustment. A short fired so closed to the target that no sighting is necessary for effective aiming. 23. Ricochet – The bouncing off or deflection of a bullet from its original trajectory (normal path) after striking a resistant surface. 24. Shocking Power – the power of the bullet that results in the instantaneous death of the victim. 25. Stopping Power – the power of the bullet that put the victim out of action instantly. So it should be understood that stopping power is not necessarily the same thing as killing power. However, stopping power depends very largely on the location of the sot. 26. Target – an object at which the firearm is aimed and discharged. 27. True Drop – the actual distance the bullet falls during the time of flight to the target. This is not the same as what we speak of when we discuss drop in the ordinary sense, which is more properly termed effective or apparent drop 28. Zero Range - This is the farthest distance at which the line of sight and the bullet's path intersect. TERMINAL BALLISTICS It is the study dealing with the effect of the impact of the bullet on the target. Penetration of the bullet is of prime interest. Penetration is important also in determining safety requirements for target backstops. They are important to both sportsman and military. TERMINAL BALLISTICS involves: 1. 2. 3. 4.

Terminal accuracy - size of the bullet grouping on the target. Terminal energy - energy of the projectile when it strikes the target. Also known as striking energy. Terminal penetration - depth of entry of the bullet in the target. Terminal velocity - speed of the bullet upon striking the target.

Terminal ballistics also deals with the destructive actions and effects that occur at the end of the projectile's flight as an integral and un-deformed body. The flight may end in one of two ways: 1. 2.

the projectile may strike a solid obstruction, or its metal case may be broken by the explosion of a bursting charge

SHOTS BALLISTICS - deals with the attributes and properties of shots and pellets. CHOKE - When the diameter of a barrel of a shotgun is the same throughout the bore, it is called true cylinder. The bore of the gun is sometimes constricted near the muzzle end. That is, the diameter near the muzzle end is slightly smaller than the diameter of the bore of the rest of the barrel. The barrel is said to be choked. Full – if reduced by one mm; half if reduced by one-half mm; quarter if reduced by ¼ mm; and improved cylinder if reduced by about 1/10 mm.

The amount of spread in the shot is controlled by the choke. If a barrel will put 70 percent of its shot charge in a 30inch (76-centimeter) circle at 40 yards (37 meters), it is called full choke. Modified choke will deliver about 60 percent; improved cylinder about 50 percent. A full choke 12-gauge gun will kill ducks that are about 60 to 65 yards (55 to 59 meters) away. Chilled Shot – shotgun pellets made from lead especially hardened by the addition of a slight amt. of antimony. WOUND BALLISTICS – It is the study of the effects of projectile to human body. Gunshot Wound (GSW). It is an open wound produced by the penetration of bullet slug within the tissues of the body. The bullet which was propelled from the gun as well as the flame from the heated expanded gases in short range fire is the one that produces injury. Three Basic Kinds of GSW Distinguished by the Proximity of the Weapon 1. 2. 3.

Contact – gun muzzle pressed against, or within an inch or two, of the body. Close discharge – 6 inches to 2 ft. Distance Discharge – over 2 ft. or 3 ft.

Range of Fire - an important aspect of forensic ballistics. 1.

2. 3. 4.

Muzzle Pattern – indicates contact wound and are often observed in suicide cases. The whole charge (projectile, wads, if any, smoke, unburnt or semi-burnt powder particles and hot gases) enter into the target. No burning, blackening and tattooing are observed. Instead, they are observed inside the hole through careful examination. The edges are found ragged (torn in star shape) and the wound is like an exit wound. Scorching – caused by the flame or hot gases not by the hot projectiles as is commonly believed. It is also known as burning or charring. Blackening – caused by the deposition of smoke particles by all types of powders at close ranges. Being light particles, they soon lose their velocity and get deposited on any material available in the path. Tattooing (a.k.a. peppering) – caused by the embedding of unburnt and semi-burnt powder particles into the surface of the target. These particles are slightly heavier than the smoke particles. They retain motion to somewhat longer intervals and consequently cause tattooing to a distance of about one and a-half times blackening range.

Other GSW Characteristics 1. 2. 3. 4.

Pink Coloration – caused by absorbed carbon monoxide in the skin and flesh. Dirt Ring – deposited by some projectile (which carry greases on them) around the wound. Existence of this indicates the entrance side of a firearm injury & does not indicate range. Contusion – caused by the impact of the projectile (reddish dark to bluish black - varies somewhat with the age of the injury). It takes the form of a belt around the wound. It is of uniform in thickness. Foreign Materials – Their presence not only permits the identification of the firearms injury but they also permit a fairly reliable guess of firearm.

Factors influencing entrance and exit gunshot wounds 1. 2. 3.

Kind of weapon - The higher power the weapon is the more destructive to the tissues of the body. Caliber of the weapon - The higher the caliber of the wounding bullet, the greater will be the size of the wound of entrance, hence, greater destruction to the tissues. Shape and composition of the missile - The conical shape free end of the bullet slug has more penetrating power but less tissue destruction, while bullet slug with hemispherical free end had less penetrating but more destruction to the tissues. * Some bullets were made to be deformed upon heating the target like the hallow point, dum-dum and soft point bullet. Bullets made of hard metals like the magnum 44 and the armor-piercing bullet are not usually

deformed upon hitting the target. Other bullets and the fragments may cause further injury to the body. The tracer bullet is in flame during its flight to the air and may caused burn upon hitting the body and this bullet is also used in targeting the low flying airplane. 4. 5.

6.

Range of fire - the injury is not only due to the missile but also due to the pressure of the heated expanded gases, flame and articles of gunpowder. However, in long range fire, the characteristic effect of the bullet alone will produce the injury. Direction of fire - A right angle approach of the bullet to the body will produce a round shape wound of entrance in short distance fire, while in acute angle of approach the bullet will produce an oval shape wound of entrance with contusion collar widest on the side of the acute angle of approach and a tendency for the bullet to deflect to another direction upon hitting the target. Part of the body involved - When the bullet hit the soft tissues of the body; the bullet penetrates and usually without any change in direction, however upon hitting the bones and other hard body structures the bullet may fracture the bones causing further injury or may deflect to another direction.

Description of the wound of entrance is based on the distance of the body from the fired gun 1.

2.

3.

Contact fire. This is burst due to the explosion of the powder which produces the heated and expanded gases. There is burning of the tissues because it is within the flame zone; singeing of the hair; and particles of gunpowder in and around the wound of entrance; skin is separated from the underlying tissues in the affected area and the blasted tissues are cherry red in color because of the presence of carbon monoxide; pressure of the bullet will caused cavingin or excavation of tissues and the contusion collar is seen around the wound of entrance. The size of the wound is rather small. Near contact up to six inches distance. There is bursting of tissues, burning and blackening of the skin as in contact fire but the particles of gunpowder are present inside as well as around the wound of entrance. The shape of the wound maybe lacerated or slit-like and the size is larger than the diameter of the missile. The excavation of tissues due to the pressure of the penetrating bullet slug but it can be severe as in contact fire. Distance above six inches up to 24 inches. The size of the wound gradually approximates the size of the missile. The farther the target, the lesser the burning or blackening of tissues, gun powder tattooing, singeing of the hair and excavation of tissues and lesser until they disappear beyond the 24 inches distance.

Differentiation between gunshot wound of Entrance and Wound of Exit Differential points 1. 2. 3. 4. 5. 6. 7. 8.

Size of the wound Edge of the wound Shape of the wound Contusion collar Gunpowder tattooing Presence or absence Protrusion of tissue Paraffin test

Wound of Entrance        

smaller than the missile Inverted Round or oval present in contact and near contact fire always present Absent + in contact and near fire

Determination whether the gunshot injury is Suicidal, Homicidal or Accidental A. Evidence to prove that gunshot wound is suicidal 1. Accessibility of the involved part to the hand of the victim 2. Usually only one gunshot wound 3. Usually the distance is short range or class range 4. Presence of suicide note 5. History of frustration or despondency of the victim 6. Presence of cadaveric spasm on the hand of the victim

Wound of Exit       

bigger than the missile Everted no definite shape absent absent maybe absent if the slug is lodged inside the body maybe present negative

7. Exclusion of other evidences to prove that it is not suicide B. Evidence that the gunshot wound is homicidal 1. 2. 3. 4. 5. 6.

Wound is located at any part of the body Victim usually at a certain distance from the assailant Signs of struggle (Defense wound) maybe present in the victim Disturbances of the surroundings. Wounding weapon usually not found at the scene of the crime Testimony from the witnesses

C. Evidence that gunshot wound is accidental 1. 2. 3. 4.

Usually only one gunshot wound Wound located at any part of the body Absence of personal grudge between the victim and the one who fired the gun Testimony from witnesses

Take note: Shotgun Wound - It is an open wound produced by the penetration of pellets or shots within the tissues of the body. In shotgun fire, the pellets penetrate and usually lodged inside the body and a tendency for a wider dispersion of pellets at a certain distance except in contact and near contact fires. Characteristics of the Shotgun Wound of Entrance 1. 2.

3. 4. 5.

Contact fire - irregular with bursting of the affected tissues due to explosion of the heated and expanded with accompanying flame causing burning of the skin and the tissues. There is singeing of the hair; presence of wads and particles of gunpowder inside the wound of entrance. Near shot up to six inches distance. There is marked laceration of the skin and destruction of tissues due to the pressure of explosion. The burning on the surface of the skin and particles of gunpowder are present inside and around the wound of entrance. There is singeing of the hair as well as pieces of wads inside and outside the wound of entrance. Distance about one yard. The pellets penetrate the tissues as one mass making the wound with irregular edge of the wound of entrance. There will also be blackening of tissues with slight burn ing, singeing of the hair or gunpowder tattooing. Distance about two to three yards. The wound of entrance has a big central hole with ragged edges and a few stray wounds of entrance around the central hole. At this distance, there will be no more blackening or burn ing of the skin, gunpowder tattooing, singeing of the hair and pieces of wads or near the wound of entrance. Distance of four yards. A small group of pellets may penetrate the tissues producing a central core, although plenty of pellets in a wider dispersion may produced separate wound of entrance. The pellets dispersed about one and a half the distance in yards in non-choked barrel while in full-choked bore the disper sion is one half less but there is a wider dispersion in short barrel shotgun.

Points to consider in the reporting of gunshot and shotgun injuries 1. 2. 3. 4. 5. 6. 7.

Detailed description of the gunshot and shotgun wound Location of wound in the body Measurement of the wound as to diameter and depth Number of wound of entrance and exit Direction and length of the bullet tract Organs or tissues involved Location of the slug if lodged in the body

8.

Diagram, photograph, sketch or drawing of the gunshot or shotgun wound

Effects or complications of wound 1. 2. 3. 4. 5.

Hemorrhage – Bleeding. It is the loss of blood from the ruptured vessel secondary to trauma or existing pathology. Direct mechanical injury - This is the direct damage to the tissues Shock - It is disturbance of the balance of fluid in the body characterized by fall in blood pressure, decreases blood flow or blood volume in the body. Infection. It is the appearance, growth and multiplication of the micro-organism in the living tissues. Embolism. It is the clogging of the blood vessel by foreign bodies such as air or bits of fats or septic embolus causing blocking to the blood flow to the distal tissues supplied by the blood.

Points to consider in the reporting of wound: 1. Character of the wound 2. Location of wound in the body 3. Measurement of the wound - It is declared in inches, centimeters and millimeters. a. Length b. Width c. Depth 4. Number of wound 5. Direction of wound 6. Organs involved 7. Severity of the wound 8. Period of healing or incapacity of the victim. Other pieces of evidence in dealing with the wound 1.

Evidence from the wounding weapon a. Presence of blood stains, bits of tissues and other body fluids on the wounding weapon. Evidence from the victim as well as the assailant a. Presence of blood stains, bits of tissues and other body fluids on the victim or assailant b. Presence of wound on the victim as well as the assailant c. Effects or complications of wound such as found in the clinical manifestations on the victim Evidence from the scene of the crime a. Presence of blood stains or drops of blood on the streets or flouring, walls, furniture and other materials at the scene of the crime b. Presence of bits of tissues, torn clothing and other body fluids at the scene of the crime

2.

3.

Take Note: SIR SYDNEY SMITH – founder of the Medico-Legal Faculty at Cairo University and later Regis Professor of Forensic Medicine at Edinburgh, was one of the leading exponents in studying entrance and exit wounds, powder burns and powder “tattooing” on human skin and other medical phenomena associated with gun fire. Studies involving Terminal and Wound Ballistics  

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1857 – Monsieur Noiles. He published a thesis titled ‘Les Plaies Feu Courtes’. His thesis dealt with the subject of wounds made by small firearms. 1889 – Mr. A. Lacassogne of Lyon, France. He published a paper tided “La Deformation Des Balles de Revolver” (Deformation of Revolver Bullets) in Volume 5. Archives de l’Antropologie Criminelle et Des Sciences Penales. 1748 - Henry Shrapnel. He invented the shrapnel, which disperse its load of case shot whit a small bursting charge, increasing the effective range of case.

Anomynous author. Published a thesis an article entitled “Entrance Wounds and Powder

 Markings”.

Mr. Louis B. Wilson. He published an article entitle “Dispersion of Bullet Energy in Relation to

 Wound Effects”.  

P. Chavigny and E. Gelma. They authored an article entitled “Fissures of the Skull by Revolver Bullets at short-range”. J. Howard Mathews. Chairman of the Department of Chemistry at the University of Wisconsin. In this first criminal case, he was involved on the metallographic analysis of bomb parts used to kill an individual.

FORENSIC BALLISTICS It is the study of Firearm Investigation and Identification of firearms by means of ammunition fired through them. This is the real branch of the science which the police use as their guide in field investigations. This includes the following: 1.

2.

3.

Field Investigations - conducted by the first officers on the case in the field when they investigate a case or cases wherein firearms have been used. This is a routine job of the investigating officers, and this involves recognition, collection, marking, preservation, and transmittal of ballistics exhibits like fired bullets, fired shells, firearms and allied matters. Technical examinations of the ballistics exhibits - This is the job performed by the firearms examiners in the laboratory. It involves marking of the evidence firearms, test firings of evidence firearms to obtain test bullets and test shells for comparative purposes, photomicrography under the bullet comparison microscope, preparation of comparative charts, and the making of reports on the findings and observations of the firearms examiners. Legal proceedings - Court Trials - wherein the ballistics report of the firearm examiner and the ballistics exhibits are presented during the trial of the case in a court of justice.

Take Note: FORENSIC - As applied to ballistics, or to any other subject, suggest a relationship to Courts of Justice and legal proceedings. FORUM – It is a Latin word from which forensic was derived, meaning a marketplace, where people gather for "public disputation" or "public discussion". Thus, the title "Forensic Ballistics" aptly describes the subject under consideration - the science of investigation and identification of firearms and ammunitions used in crimes. The terms "Ballistics", Forensic Ballistics" and "Firearms Identification", have come to mean one and the same thing in the minds of the public, and they can be used interchangeably. Studies concerning Forensic Ballistics 

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1835 - Henry Goddard. In one of his case in England, where a homemaker was shot and killed, he was able to identify the mold mark – the mold is used to manufacture lead balls from molten leads – on the field projectile. He was the bullet, which could be traced back to the mold. He also examined the paper patch – the paper patch provides the seal between the ball gunpowder firearms – was able to identify it as having been torn from a newspaper that was found on the room of the guilty servant. Paul Jesrich. He took photomicrographs of two bullets to compare, and subsequently individualize them through the minute differences. 1905 - Mr. Kockel. He published an article entitled “The Expert Examination of Fired Bullets”. 1912 - Professor V. Baltahazard. He devised a series of procedures to identify fired bullets to the firearms from which they were fired. He studied the firearms by taking an elaborate series of photographs of test fired bullet from the firearms as well as evidence bullet. He also applied these same specilalized photographic techniques to the examination and identification of cartridge casings using firing pin, breech face, ejection and extractor marks. 1913 - Professor Balthazard. Published the first article individualizing bullet markings. 1922 - Mr. C. Williams. He wrote an article entitle “Fingerprints on Bullets” which appeared in Outdoor Life magazine. 1920 - R.E. Herrick. He published an article entitled “Ballistics Jurisprudence”.

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November 1924 – Dr Sydney Smith. He wrote an article concerning the details of the investigating that appeared in the British Medical Journal in January 1926. He relates that he believes that scientific examination of firearms and projectiles in Great Britain had its beginning as a result of the publication of his report on the case. 1920 - COL CALVIN H. GODDARD (M.D., U.S. ARMY) pioneered the introduction of this science in Criminology courses in the different universities. 1947 - Col Goddard came to the Philippines when Gen. Castaneda was ambushed together with his aid, Col Salgado in Kamias, Quezon City, both died. 1924 – Captain Edward C. ‘Ned’ Crossman. A well-known shooter and sports writer, examined firearms evidence for the Los Angeles County Sheriff in April 1925, in New York City, New York (USA), THE Bureau of Forensic Ballistics was established by C.E. Waite, Major (later Colonel) Calvin H. Goddard, Philip O. Gravelle and John H. Fisher. 1934 - Major Sir Gerald Burrard. He wrote a book entitled “The Identification of Firearms and Forensic Ballistics”, which discussed many early cases that occurred throughout the British Empire. 1935 Major Julian S. Hatcher. He wrote and published; “Textbook of Firearms Investigation, Identification and Evidence” together with the “Textbook of Pistols and Revolvers.” 1944 – John E. Davis. He joined the Police Department in Oakland, California establishing its first criminology laboratory. Derechter and Mage. They wrote an article entitled “Communication on the Identification of Fired Bullets and Shells”. Arthur Lucas. He published an article entitled “The Examination of Firearms and Projectiles in Forensic Cases”. Jack D. Gunther & Professor Charles O. Gunther. They published the entitled “The Identification of Firearms”, which provided additional information about the principles of firearms identification with approximately one-half of the book discussing in great detail the Sacco-Vanzetti case to include reprinting large portions of the actual court transcript. They also discussed the need for the science of firearm identification to utilize the scientific methodology. 1958 – John E. Davis. An eminent criminals and Director of the Oakland Police Department (CA) Criminalistics Section (Crime Lab) wrote a book titled “An Introduction to Tool Marks, Firearms and the Striagraph”. In his book, Davis provided excellent information about the examination and identification of firearms and tool mark evidence. 1996 – Tom A. Warlow. He published a text on firearms identification titled “Firearms, the Law and Forensic Ballistics”. Warlow has written a useful text that contains excellent information for firearm and toolmark examiners. 1997 – Brian J. Heard. He published a text on firearms identification titled “Handbook of Firearms and Ballistics Examining and Interpreting Forensic Evidence”.

SUBJECTS OF BALLISTICS STUDY FIREARMS A firearm is a weapon that fires either single or multiple projectiles propelled at high velocity by the gases produced through rapid, confined burning of a propellant. This process of rapid burning is technically known as deflagration. In older firearms, this propellant was typically black powder, but modern firearms use smokeless powder or other propellants. The term gun is often used as a synonym for firearm, but in specialist use has a restricted sense—referring only to an artillery piece with a relatively high muzzle velocity and a relatively flat trajectory, such as a field gun, a tank gun, an anti-tank gun, or a gun used in the delivery of naval gunfire. Firearms are sometimes referred to as small arms. Small arms are weapons which can be carried by a single individual, with a barrel bore of up to approximately 0.50 inch (12.7 mm). Small arms are aimed visually at their targets by hand using optical sights. The range of accuracy for small arms is generally limited to about one mile (1600 m), usually considerably less, although the current record for a successful Sniper attack is slightly more than 1 1/2 miles. Firearm (Technical) is an instrument that is used for the propulsion of projectile by means of the expansive force of gases of burning gunpowder. Firearms or Arm (legal – Sec. 877 of the RAC and Sec. 290 of NIRC) – includes rifles, muskets, carbines, shotguns, pistols, revolvers and all other weapons from which a bullet, a ball, a shot, a shell or missiles may be discharged by means of

gunpowder or other explosives. The term also includes air rifles, except that are in small in caliber and usually used as toys. The barrel of any firearm is considered a complete firearm for purposes of Section 877 of the Revised Administrative Code. Take Note:      

Rifle – long rifle bored firearm designed to hit targets at a greater or longer distance, with spiral grooves to fire only a single shot. Musket – long smooth bored firearm that is designed to prepare a single shot. Shotgun – long smooth bored firearm having a barrel of 25-30 inches long and designed to shot birds in flight; long smooth bored firearm and breech loading designed to fire a number of lead pellets or shot in one charge. Carbine – s short barrel rifle, having a barrel not longer than 22 inches and it is designed to fire a single shot through a rifled-bore, either semi-automatic or full automatic, for every press of the trigger. .22 – minimum caliber - .19 - .18 – if only used as toys, could not be considered as firearm. barrel of any firearm - Possession of any part of a firearm is considered a violation of illegal possession of firearm (SCRA Dec. 11, 1992).

FIREARM: IN ITS GENERAL CONTEXT Firearm is any weapon that uses gunpowder to fire a bullet or shell. Generally, the term is used for light firearms, such as rifles, shotguns, and pistols. They are often called small arms. Heavier firearms are generally referred to as artillery. Mechanism Any firearm, large or small, has four essential parts: 1.

Barrel – It is a long tube. It may be smooth, as in a shotgun, or with spiral grooves on the inner surface, as in a rifle.

2.

Chamber - It is a widened hole at the breech (rear) end of the barrel. It holds the cartridge (explosive charge).

3.

Breech mechanism - The breech mechanism closes the rear end of the barrel, holding the cartridge in the chamber.

4.

5.

Every up-to-date firearm has some way by which the breech can be opened for loading and locked for safety in firing. Artillery uses screw plugs or breechblocks. Machine guns, rifles, and other small arms usually have a metal cylinder, or bolt, that is locked when the gun is fired, and drawn back to eject (force out) the empty cartridge case and to reload. Firing mechanism - The firing mechanism may be electric, as in some large artillery pieces. In small arms, a spring drives a pointed firing pin through the breech bolt against a sensitive primer in the cartridge. The firing pin is cocked (drawn back) against a hook called the sear. When the trigger is pulled, the sear releases the firing pin, which in turn leaps forward to strike the primer. A jet of flame from the primer ignites the rest of the powder, forming a gas. This explosive gas propels the bullet from the barrel.

HANDGUN/SHORT ARMS 1. 2.

Pistol – a handgun that is magazine feed. It is said that pistols were invented in the Italian town “PISTOIA.” Hence, the name pistol – arrived in Britain about 1515 as German import. Revolver – A handgun with a corresponding cylinder that revolves before the barrel which consist of different chambers.

ORIGINS OF FIREARMS 

13th Century – development of firearms followed the invention of gunpowder in Western Europe.

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BERTHOLD SCHWARTZ – a German monk, and Roger Bacon, an English monk – are both credited with gunpowder invention. * Most reference books credit Roger Bacon, English monk and scientist, with the invention of gunpowder in 1248, and Berthold Schwartz, with the application of gun powder to the propelling of a missile in the early 1300’s. This powder was that we now call “black powder”.

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1118 – Moors used artillery against Zaragoza. Early manuscripts tell o fseveral Moorish campaign in which artillery was used all dating prior to Bacon and Scwartz. 1245 – Gen. Batu, the Tartar leader used artillery in Liegnitz when he defeated the Poles, Hungarians and Russians. * It is also often stated that gunpowder was first invented by Chinese were aware of gunpowder and its use as a propellant long before its advantage became recognized in Europe. It may also assume the Arabs with their advance knowledge of chemistry at that time.

1247 – one of the earliest recorded uses of firearms in warfare was that o fan attack on Seville, Spain. 1346 – Cannons used by King Edward III of England at Crecy 1453 – Mohammed II of Turkey in his famous conquest of Constantinople. 1500 AD - French Artist LEONARDO DA VINCE as can be gleaned in his sketch of steam powered cannon to his primitive wheel lock firearm. * First firearms were inefficient, large and heavy and were not capable of being carried by an individual soldier hence; the development of cannons preceded that of small arm weapons by almost 50 years.

Stages of development of man’s weapon: > STONES > CLUBS > KNIVES > SPEARS AND DARTS > SLINGSHOTS TO HURL OBJECTS > BOWS AND ARROWS > CROSS-BOWS >GUNS > MISSILES Contributors in Firearms Development             

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Col. Calvin H. Goddard, Md., OS, U.S. Army – Father of Modern Ballistics Horace Smith – Founded the great firm Smith & Wesson and pioneered the making of breech-loading riffles. Daniel B. Wesson – An associate or partners of Smith in revolver making. John M. Browning – Wizard of modern firearms and pioneered the breech loading single shot riffle. John T. Thompson – Pioneered the making of Thompson Sub-machine gun. David “Carbine” Williams – maker of first known carbine. Alexander John Forsyth – Father of the percussion ignition. Elisha King Root – Designed machinery of making Colt firearms. Eliphalet Remington – one of the first riffle makers. John Mahlon Marlin – founder of Marlin Firearms Company. James Wolfe Ripley – Stimulated the development of the Model 1855 riffled-musket. Samuel Colt (1814-1862) - of Hartford, Connecticut, produced the first practical revolver bringing it to what most gunsmiths would agree was its perfect form in the Colt Army 1873 model, which became famous for its .45 caliber. Other manufacturers followed Colt’s lead: Remington and Smith and Wesson in the US., Adams and Scott-Webley in BRITAIN, Star, Luger, Browning and Beretta on the CONTINENT, until revolvers were in used in every part of the world. Henry Derringer – He gave his name to a whole class of firearms (Riffles and pistols) John C. Garand – Designed and invented the semi-automatic US Riffle, Cal. .30 MI Oliver F. Winchester – one of the earliest riffles and pistol makers. John Dreyse (1841) - Invented a breech-loading infantry rifle, the so called needle gun because of its long sharp firing pin. Maj. Cavalli of Sardina (1845) - He develop a serviceable breech loading artillery rifle.

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Carl Walther (1866) - Develop a reliable small caliber automatic Pistol. Paul Withelm Mauser (1871) - Produced parts of the rifle which had been adopted by the German government. Sergei Mossin (1891) - Designed the Russian Service rifle. Kijiro Nambu (1904) - An army gun designer whose design was first produced by the Kayoba factory. Charles Dorchester & George Sullivan (1950) - Formed the Armalite business.

IMPORTANT DATES IN FIREARMS HISTORY 1313 – Gunpowder as a Propellant. The age of gunpowder began with its first use as a propellant for a projectile. Such use has been recorded as early as 1313. 1350 – Small Arms. Gunpowder was first used only in cannons. It was in the middle of the 14 th century that portable hand firearms were introduced. These guns were ignited by a hand-held hot wire or lighted match. 1498 – Riflings. The first reference to riffled barrels appeared. Although it’s important as an aid to accuracy was recognized by some, it was a year after before riffling was generally used. 1575 – Cartridge. Paper cartridge combining both powder and ball were developed. This greatly speeded loading and reduced the hazards of carrying loose powder. 1807 – Percussion System. The discovery of Forsyth in 1807 that certain compounds detonated by a blast would be used to ignite the charge in a firearm, for the basis for all later percussion and cartridge to come into general use. 1845 - Rimfire Cartridge. In France, Flobert developed a “bullet breech cap” which was in reality the first rim fire cartridge. 1858 – Center fire Cartridge. The Morse cartridge o f1858 marked the beginning of the rapid development of the center fire cartridge. 1884 – Automatic machine-gun. Hiram Maxim built the first fully automatic gun, utilizing the recoil of the piece of load and fire the next charge. 1885 – Smokeless Powder. In France, Vieille developed the first satisfactory smokeless powder, a new propellant which not only lacked the smoke characteristic of black powder, but also more powerful. MECHANISMS OF FIREARM ACTION Generally, the principles involved in all firearms action are the same. When the firearm is cocked and ready to fire, a pull on the trigger will cause the firing pin of the hammer to hit the percussion cap of the cartridge in the firing chamber which is aligned with the rear portion of the barrel. The hit by the firing pin on the percussion cap will cause generation of a sufficient heat capable of igniting the primer. The primer will in turn ignite the gunpowder or propellant which will cause evolution of gases under pressure and temperature. The marked expansion of the gases will force the projectile forward with certain velocity. Owing to presence of the rifling at the inner wall of the bore, the barrel offers some degree of resistance to the projectile. In as much as the riffling is arranged in a spiral manner, the projectile will produce a spinning movement as it comes out in the muzzle. Together with the bullet passing out of the barrel are high pressure heated gases, unburned powder grains with flame and smoke.

During explosion, there is a backward kick of the firearm which in automatic firearm cause the cocking and the cartridge cause thrown out by the ejector. The backward movement is called recoil of the firearm. RIFLING Rifling refers to spiral grooves that have been formed into the barrel of a firearm. It is the means by which a firearm imparts a spin to a projectile to gyroscopically stabilize it to improve accuracy. Most rifling is created by either cutting with a machine tool, pressed by a tool called a "button" or forged into the barrel over a "mandrel". The grooves are the spaces that are cut out, and the resulting ridges are called 'lands'. These lands and grooves can vary in number, depth, shape, direction of twist ('right' or 'left'), and 'twist rate' (turns per unit of barrel length). The spin imparted by rifling significantly improves the stability of the projectile, improving both range and accuracy. It consists of the number of the helical grooves cut on the surface of the bore, it includes the lands and grooves are running parallel with one another concentrically.

* Sporting Rifle As a bullet is fired from a rifle, grooves in the interior of the barrel cause it to spin. The spinning motion stabilizes the bullet and increases its distance and accuracy. This illustration shows a modern hunting rifle and highlights its main components. Take Note: Recent developments - The grooves most commonly used in modern rifling have fairly sharp edges. More recently, polygonal rifling has become popular, as it seems to produce better accuracy due to the fact that it does not damage the bullet as badly as conventional rifling. Polygonal barrels also tend to have longer service lives because the reduction of the sharp edges of the land reduces flame erosion. Higher velocities may be generated due to a reduction of friction and an improvement of the gas seal between the bullet and barrel. A disadvantage of polygonal rifling is that if simple lead bullets are used, lead from the bullet tends to accumulate in the barrel (called leading) resulting in a dirty barrel, poor accuracy, and if the leading becomes severe, excessive chamber pressure which could cause a barrel or locking failure. Polygonal rifling is currently seen on most pistols from GLOCK and Kahr Arms. CALIBER OF THE FIREARM The caliber of the firearm is the diameter of the bore of the barrel measured from land to land in rifled firearm. It is expressed in inches or fraction of an inch by the American and English manufacturers and millimeters or in centimeters there by manufacturers in Continental Europe.

THE RIFLE The rifle, invented about 1500, had spiral grooves in the barrel that made it more accurate than any previous firearm. Smokeless powder was developed in the 1800's. Breechloading systems replaced dangerous muzzle loading. Many improvements since have resulted in high-powered firearms. Rifle is a gun with spiral grooves in its long barrel that spin the bullet as it is shot. Rifles are usually held against the shoulder when firing. Soldiers use rifles in battle. People also use rifles to hunt game and to compete in shooting matches. The parts of a rifle - All rifles have four basic parts: (1) the barrel, (2) the stock, (3) the action, and (3) the sights. How a rifle works. A rifle is ready to be fired when a cartridge has been fed into the firing chamber. Then the rifle is aimed and the trigger squeezed. The rifle's hammer or firing pin strikes the rear end of the cartridge and ignites the primer. The primer in turn ignites the propellant powder in the cartridge. The powder burns rapidly, creating pressure that drives the bullet down the barrel. The rifling in the barrel makes the bullet spin. Without spin, a bullet would not stay pointed forward in flight, but would tumble over and over. The spinning motion increases the accuracy of a bullet. Kinds of Rifles Rifles are classified by:   

type of action: (manually operated, automatic, or semiautomatic); the name of the designer or manufacturer (for example, Remington or Winchester); or caliber. Caliber may refer to the inside diameter of the barrel or the diameter of the bullet. The caliber is measured in millimeters or in decimal fractions of an inch.

There are three kinds of repeating rifles with hand-operated actions-bolt-action, lever-action, and slide-action. These rifles have magazines (cartridge holders) that feed cartridges into the firing chamber. The action on two other kinds of rifles-automatic and semiautomatic-is operated by forces caused by the burning of the propellant powder in the firing chamber. 1. 2. 3.

Bolt-action rifles have an action that resembles a bolt used to lock a door. When the bolt on the rifle is pulled back, the used cartridge is thrown out and the hammer is cocked. When the bolt is moved forward, it pushes a new cartridge into the firing chamber. Lever-action rifles are loaded by moving a lever under the breech down and back up. The down movement throws out the used cartridge and cocks the hammer. The up movement inserts a new cartridge into the firing chamber. Slide-action rifles, also called pump-action rifles, are loaded with a back-and-forth movement of a rod and handle beneath the front part of the barrel. When the handle is pulled back, the breech opens and the used cartridge is thrown out. A live cartridge is inserted when the handle is pushed forward.

Automatic and semiautomatic rifles are used mainly by soldiers and police officers. When a rifle is fired, gas is formed by the burning powder in the firing chamber. The expanding gas drives the bullet out of the barrel. In most modern automatic and semiautomatic rifles, some of this gas operates the action. When a cartridge is fired, a fresh cartridge is moved out of the magazine into the firing chamber, and the firing mechanism is cocked. The M16A2 is the automatic rifle used by the U.S. armed forces. It weighs 8.9 pounds (4 kilograms) when loaded with a 30-cartridge magazine. The M16A2 can fire one shot at a time, or three shots in a single burst. It uses a 5.56-millimeter cartridge.

Rifle cartridges are enclosed in a casing (metal covering) made of brass or steel. Cartridges vary in size according to the caliber of the rifle. The names of some cartridges include the year the cartridge was put into use. The .30-06 is a .30-caliber cartridge chosen for use by the U.S. Army in 1906. The classification of some cartridges includes the caliber and velocity (speed) of the bullet. The bullet from a .250-3000 cartridge has a velocity of 3,000 feet (910 meters) per second. Take Note: Modern rifles developed from the crude, muzzle-loading firearms of the 1400's. Rifling of barrels was invented in Europe about 1500. Smooth-bore firearms (weapons without rifling) could not be depended on to hit targets more than 100 steps away. The jaeger rifle of central and northern Europe was the first accurate rifle. It was developed about 1665. German immigrants brought jaegers to Pennsylvania in the early 1700's and gave them new features, including longer barrels. The Pennsylvania-made Kentucky rifle developed from the jaeger. Some Kentucky rifles were used in the Revolutionary War in America (1775-1783). Rifles used round bullets until the 1850's, when more accurate Minie bullets became popular. Minie bullets had hollow bases and pointed tips and were used in the U.S. Civil War (1861-1865). Improvements of the late 1800's included repeating rifles, smokeless explosive powder, and jacketed bullets, which have a tough metal cover over a lead or steel core. THE HANDGUN: Handgun is a firearm that can be operated with one hand. Other types of guns, such as rifles and machine guns, require the use of both hands, a tripod (three-legged stand), or a shooting rest. Parts of a handgun (the frame, the grip, the barrel, the sights, and the action) The frame is the main body of the gun that connects the other parts. The grip is the handle of the gun, and the barrel is the metal tube through which the bullet is fired. The lands and rifling (grooves) are alternating raised surfaces and channels inside the barrel. They cause the bullet to spin and thus make it travel in a direct path. The shooter uses the sights to line up the handgun with the target. Some sights can be adjusted to help aim the gun more easily. All handguns made for target shooting have adjustable sights. The action includes the main working parts of the handgun. It consists of such parts as the trigger, the hammer, and the cartridge chamber. The type of action determines how the handgun is loaded and fired. The action of every handgun includes a safety, a mechanism that prevents the gun from being fired unintentionally. The safety ensures that the gun fires when the shooter squeezes the trigger, but not, for example, when the gun is dropped to the ground. Types of handguns - There are five main types of handguns: 1. 2. 3. 4. 5.

single-action revolvers, double-action revolvers, single-action semiautomatic pistols, double-action semiautomatic pistols, and single-shot pistols.

Revolvers carry ammunition in chambers in a rotating cylinder. Most pistols are loaded with a magazine containing the ammunition. The magazine is a metal holder inserted in the gun's butt (thicker end). Single-action revolvers typically hold six cartridges. An arm near the hammer rotates the cylinder one-sixth of a turn when the hammer is cocked. This movement puts a cartridge into line with the barrel and the firing pin (part that strikes the primer to fire the cartridge). After cocking the hammer, the shooter pulls the trigger. The hammer unlocks and falls, exploding the cartridge. The Colt single-action Army revolver, first produced in the 1870's, is the most famous firearm of this type.

Double-action revolvers, like single-action revolvers, typically hold six cartridges. But, unlike single-action revolvers, double-action revolvers do not require the user to manually cock the hammer before firing. Instead, the gun is fired by only pulling the trigger. When the trigger is pulled, a lock that holds the cylinder in place is released, revolving the cylinder and cocking the hammer. When the next chamber is lined up with the barrel, the cylinder locking bolt is raised into the locking notch, securing the cylinder. The hammer then falls and fires the cartridge. The cycle is repeated for the next shot. The main advantage of the double-action revolver over the single-action revolver is that it can be fired rapidly. The Smith & Wesson military and police revolver is one of the most popular double-action revolvers. This firearm was introduced in 1905. Single-action semiautomatic pistols are fired by first pulling back a device called a slide to cock the hammer or the firing pin, which is sometimes called a striker mechanism. When the slide is released, it moves forward and feeds a round from the clip into the cartridge chamber. When the shooter pulls the trigger, the hammer falls or the striker mechanism is released, impacting the primer and exploding the gunpowder in the cartridge. The explosion causes the slide to move backward. This recoil automatically ejects the empty cartridge and recocks the gun. When the slide moves forward again, it reloads the chamber. The most famous single-action semiautomatic is the Colt .45 automatic pistol. It served as the standard sidearm of the U.S. armed forces from 1911 until 1985. Double-action semiautomatic pistols operate somewhat like double-action revolvers. When the trigger is pulled, the hammer goes through the firing cycle and fires the cartridge. After the initial shot, the pistol begins to operate like a single-action semiautomatic pistol. The recoil of the first shot forces out the empty cartridge case, cocks the hammer, and inserts a new cartridge from the clip into the cartridge chamber. Double-action semiautomatics are widely used by sports enthusiasts and police officers. In 1985, the 9-millimeter Beretta, a double-action semiautomatic pistol, became the standard sidearm of the U.S. armed forces. Other popular models include the Smith & Wesson Model 39 and the Walther PPK. Single-shot pistols are used chiefly in international target-shooting competitions. To load a single-shot pistol, the user moves the operating lever (part that opens and closes the action) forward and down to lower the breech block and to cock the firing pin. The breech block closes the breech of the gun-that is, the part behind the barrel. After the breech block has been lowered, the cartridge chamber is exposed. The user then inserts a cartridge into the chamber. Next, the operating lever is pulled up and back to close the chamber and move the cartridge into the closed position. The pistol is then ready to fire. When the trigger is pulled, the firing pin drops, exploding the cartridge. The procedure is then repeated to remove the cartridge and reload the pistol. Famous single-shot pistols include the Hammerli Free Pistol, the Walther, and the Martini. Take Note: The first gun operated with one hand was the matchlock gun, which appeared in the 1400's. It was fired by attaching a burning cord or match to an S-shaped holder called a serpentine. In the early 1500's, the wheel-lock gun was invented. Its metal wheel struck a spark when it revolved against a piece of pyrite. With the wheel lock, soldiers no longer had to carry flames to ignite the gunpowder. During the mid-1500's, snaphance pistols, which were easier to operate than the wheel lock, came into widespread use. In the 1600's and 1700's, many kinds of gunlocks were developed, including the flintlock. In 1807, Alexander Forsyth, a Scottish inventor, introduced the percussion system. Percussion-system pistols were loaded from the muzzle, with a sliding can of priming powder on the breech. Small handguns called derringers are descended from percussion-system pistols, but are breech loaded. They are named for Henry Deringer, Jr., a U.S. pistol maker of the 1800's. Rapid-fire handguns - One of the first practical revolvers was the Colt Paterson, patented in England in 1835 by Samuel Colt, a U.S. inventor. In 1857, the U.S. inventors Horace Smith and Daniel Wesson began producing revolvers that used cartridges. The Borchardt, the first self-loading semiautomatic pistol, appeared in 1893. It had an eight-cartridge clip placed in the hollow of the grip. George Luger, an Austrian-born inventor, improved the Borchardt in the early 1900's. In 1897, John M. Browning, a U.S. inventor, patented an automatic pistol that became the basis for later automatics, including the Colt .45. THE MACHINE GUN

1.

Machine gun is an automatic weapon that can fire from 400 to 1,600 rounds of ammunition each minute. Machine gun barrels range in size from .22 caliber to 20 millimeters. Ammunition is fed into the gun from a cloth or metal belt, or from a cartridge holder called a magazine. Because machine guns fire so rapidly, they must be cooled by air. Machine guns are heavy weapons and are usually mounted on a support. Operation: In all machine guns, extremely high gas pressure provides the operating energy for the firing cycle. The cycle begins when the propellant charge in the cartridge case burns. This combustion creates the gas pressure that is used in the blowback, gas, and recoil operating systems. All three systems fire the projectile through the bore of the barrel, eject the cartridge case, place a new cartridge in the firing chamber, and ready the mechanism to repeat the cycle. In the blowback system, the operating energy comes from the cartridge case as the case is forced to the rear by the gas pressure. The case moves against the bolt (a device that opens and closes the bore), driving the bolt backward against a spring. The case is ejected, and the compressed spring drives the bolt forward. As the bolt moves forward, it cocks the firing mechanism, picks up a new cartridge, carries it into the chamber, and the cycle begins again. In the gas system, the gas pressure drives a piston against the bolt. The bolt is driven to the rear, providing energy for a cycle like that of the blowback system. In the recoil system, the bolt locks to the barrel when the gun is fired. These parts remain locked together as they are forced to the rear by the gas pressure. This movement provides energy to operate the gun.

2.

Ground weapons. The 7.62-millimeter M60 machine gun is a major infantry weapon. It is air-cooled and gas-operated, and fires about 600 rounds a minute. The M60 replaced the Browning machine gun, an important weapon in World Wars I and II, and the Korean War.

3.

Aircraft weapons. By the close of World War I, several types of machine guns were mounted on airplanes. These types included the Vickers, Maxim, Hotchkiss, Colt-Martin, and Lewis. Some machine guns were synchronized to fire in between the blades of propellers. During World War II, fighters and bombers carried machine guns as armament. They also carried automatic cannon up to 20 millimeters in size. During the Vietnam War, airplanes and helicopters called gunships carried machine guns or cannon. Today, most fighter planes and gunships carry rockets for air-to-air and air-to-ground use. Bombers use machine guns mounted in groups of two or four in power-driven turrets. The Vulcan 20-millimeter aircraft cannon has six rotating barrels. It can fire more than a ton of metal and explosives each minute.

4.

Anti-aircraft weapons. The .50-caliber Browning machine gun was used as an antiaircraft weapon during World War II. It was used alone, or in groups of two or four. Large-caliber automatic cannon that fired explosive shells were also developed as antiaircraft weapons. The 20-millimeter, Swiss-made Oerlikon gun was used on U.S. Navy ships. It was a self-fed, self-firing cannon that could fire 600 rounds a minute. Take Note: A type of machine gun appeared as early as the 1500's. It consisted of several guns bound together in a bundle or spread out in a row. A device that was fitted to the gun barrels caused them to fire simultaneously or in series. But little success was achieved until the Civil War, when many quick-fire guns appeared. Practical, rapid-fire, mechanical guns were used in the Franco-Prussian War, when soldiers operated them with a crank or lever. The French Montigny mitrailleuse and the American Gatling were among the more successful of these guns. In 1883, Hiram Maxim, an American-born inventor, developed the first entirely automatic machine gun to gain wide acceptance. By the time of World War I, many different types of machine guns had come into use. CLASSIFICASTION OF FIREARMS A. ACCORDING TO GUN BARREL INTERNAL CONSTRUCTION

1. 2.

Rifled Bore Firearms - those that contain riflings inside the gun barrel. Riflings refers the lands and grooves such as the following: Rifle – Pistol - Revolver Smooth Bore Firearms – those that have no riflings inside the gun barrel for the breech end up to the muzzle of the firearm. Such as the following: Shotguns - Muskets SHOTGUN – it is smooth bore firearm designed to shoot a number of lead pellets one discharge. GAUGE – as applied to shotgun indicates that the bore diameter is equal to the diameter of lead ball weighing in

pounds. B. MAIN TYPES OF FIREARM (according to caliber of projectile) 1. Artillery – propelled projectile is more than one inch in diameter. Ex. Cannons, mortars, bazookas 2. Small Arms – propelled projectile is less than one inch diameter. Ex. Machine guns, shoulder arms and handguns/arms C. TYPES OF FIREARMS ACCORDING TO MECHANICAL CONSTRUCTION 1. Single Rifle Firearms – type of firearm designed to fire only one shot for every loading. Example: Pistol, Rifle, Shotgun 2. Repeating Arms – type of firearm designed to fire several shots in one loading. Example: Automatic pistols, Revolvers, Rifles, Shotguns 3. Bolt Action Type – reloading is done by manipulation of the bolt. Examples: Rifles, Shotguns. 4. Automatic Loading Type – after the first shot is fired, automatic loading or feeding of the chamber takes place. Examples: Rifles, Shotguns 5. Slide Action Type (Trombone) – loading takes place by back and forth manipulation of the under forearm of the gun. Examples: Rifles and Shotguns. 6. Lever Type (Break-type) – loading takes place by lever action on the firearm. Examples: Rifles, Shotguns. D. TYPES OF FIREARMS ACCORDING TO USE 1.

2.

3.

Military Firearms a. Pistols d. Shotguns b. Revolvers e. Machine guns c. Rifles Pocket and Home Defense Firearms a. Pistols c. Rifles b. Revolvers d. Shotguns Target and Outdoorsman known as Sporting a. Pistols b. Revolvers

c. Rifles

E.

UNUSUAL/MISCELLANEOUS TYPES – those that are unique in mechanism and construction. a. Paltik pistols b. Paltik rifles c. Paltik revolvers d. Paltik shotguns

F.

CLASSIFICATION OF FIREARMS ACCORDING TO ITS POWER PURSUANT TO R.A. 8294

Section 1. Unlawful Manufacture, Sale, Acquisition, Disposition or Possession of Firearms or Ammunition or Instruments used or intended to be used in the Manufacture of Firearms or Ammunitions. The penalty of prision correctional in its maximum period and a fine of not less than Fifteen thousand pesos (P15,000.00) shall be imposed upon any person who shall unlawfully manufacture, dealt in, acquire, dispose or possess any low-powered firearm, such as rimfire handgun, .380, .32 and other firearm of similar firepower, part of firearm, ammunition or machinery, tool or instrument used in the manufacture of any firearm or ammunition: provided, that no other crime was committed. The penalty of prision mayor in its minimum period and a fine of thirty thousand pesos (P30,000.00) shall be imposed in the firearm is classified as high powered firearms which includes those with bore bigger in diameter than caliber .38 and 9mm such as caliber .40, .44, .45 and also lesser caliber firearms but considered powerful such as caliber .357 and caliber .22 center fire magnum and other firearms with firing capability of full automatic and by burst of two (2) or three (3): Provided, however, that no other crime was committed by the person arrested.

G. THREE MAIN PARTS OF FIREARMS 1.

Revolver a. barrel assembly b. cylinder assembly c. frame or receiver

3. Rifle – Cal. .30 a. barrel assembly b. magazine assembly c. stock group

2.

Pistol a. barrel assembly b. slide assembly c. frame or receiver

4. Shotgun a. barrel assembly b. magazine assembly c. stock group

H. DETAILED PARTS 1. Revolver 1. Barrel Assembly (1) breech end (2) muzzle end (3) bore (4) riflings (5) front sight (6) make

2. Cylinder assembly (1) chambers

2. Pistol a. Barrel Assembly (1) breech end (2) muzzle end (3) bore (4) riflings (5) chamber (6) interlocking ribs (7) barrel lug (8) barrel link (9) barrel link pin (10) barrel lead (leed) b. Slide Assembly (1) front sight

(2) (3) (4) (5) (6) (7)

extractor extractor rod racket cylinder grooves yoke cylinder locking notches (touch holes)

3. Frame or Receiver (1) top strap (2) rear sight (3) breech face (4) hammer (5) spur (6) thumb latch (7) side plate (8) back strap (9) firing strap (10) butt (11) front strap (12) trigger guard (13) trigger (14) cylinder lock (15) right side stock (16) left side stock (17) trade mark (monogram) (18) serial number I.

(2) top strap (3) ejection part (4) rear sight (5) breech block (6) breech face (7) extractor (8) firing pin (9) firing pin stop (10) serrations (11) trademark (12) model (13) interlocking lugs c. Frame or Receiver (1) ejector (2) hammer (3) spur (4) grip safety (5) disconnector (6) thumb safety (7) back strap (8) butt (9) lanyard loop (10) front strap (11) magazine well (12) right side stock (13) left side stock (14) trigger (15) trigger stock (16) modes (17) plunger (18) serial number

AUXILIARY PARTS (ACCESSORIES) The following parts must be removed first before disassembly of the weapon: - recoil plug - recoil spring - barrel bushing - recoil spring guide - slide stop pin

J.

ADVANTAGES 1.

Revolver

   

almost everyone knows something about how to handle it. safer for inexperienced people. the mechanism allows the trigger pull to be better. a misfire does not put the revolver out of action.



Can handle satisfactory old or new or partly deteriorated ammunition which reduces velocity.

2.

Automatic pistol

      

has a better grip, fits the hand and points naturally more compact for the same fire power easier to load, easier to clean barrel when worn or corroded can be replaced without sending the gun to the factory gives greater number of shots gives greater fire power and greatest ease in firing no gas leakage during firing

K. DISADVANTAGES

L.

1.

Revolver

     

bulkier to carry grip or handle is generally not as good as that of pistol hard to clean after firing slower to load harder to replace worn out parts – it’s a factory job worn out or poorly made weapon is subject to variable accuracy to improper lining up of cylinder

2.

Automatic Pistol

         

ammunition must be perfect – it causes jam misfire stops the functioning of gun when kept loaded for long period of time – magazine spring is under tension has poorer trigger pull magazine requires jacketed bullet more dangerous to handle especially for inexperienced people usually not adopted for reloading possible ejection of empty shell towards the face of the firer causing flinching throws out empty shell on the ground to remain as evidence cannot be fired from the pocket without jamming

PRECAUTION FOR REVOLVERS Every police officer should frequently check his revolver for: 1. obstruction in the barrel 2. bulging or swollen barrel 3. firing pin protrusion through recoil plate when trigger is in rearward position 4. on older revolvers, the imprint of the primer on the recoil plate in relation to the firing pin hole (insures blow in the center of primer)

5. 6. 7. 8.

evidence of “splitting lead” around breech of barrel or for complaints of fellow shooters tightness of all side plate screw tightness of ejector rod head if the weapon is S & W cleanliness and protective film of oil to prevent rust

AMMUNITIONS/CARTRIDGES LEGAL DEFINITION – it maybe found in Chapter VII, Sec. 290 of the National Internal Revenue Code as well as in Sec. 877 of the Revised Administrative Code. It refers to ammunition as s “loaded shell” for rifles, muskets, carbines, shotguns, revolvers and pistols from which a ball, bullet, shot, shell or other missile may be fired by means of gunpowder or other explosives. The term also includes ammunition for air rifles as mentioned elsewhere in the Code. TECHNICAL DEFINTION – Technically speaking, the term ammunition refers to a group of cartridges or to a single unit or single cartridge – meaning a complete unfired unit consisting of a bullet, cartridge, case, gunpowder and primer. The term may also refer to a “single round”. ORIGIN The term “cartridge” evolved from about the turn of sixteenth century. The earliest small arms ammunition or cartridge consisted of a pre-measured charge of powder wrapped in a paper. In Webster’s later edition, a cartridge is defined as “A case capsule, shell or bag of metal, pasteboard, of the like, containing the explosive charge and in small arms and some cannon, the projectile to be fired. The term cartridge is derived from the word “charta”, the Latin word for paper. Later on, it came through the French word “cartouche”, meaning a roll of paper, which indicates that the original cartridges were not the brass gildingmetal tipped units which we are familiar with today. The use of paper-wrapped powder charged greatly speeds the loading of military weapons, avoided waste of powder from spillage, and provided a uniform charge from shot to shot. In time, the bullet was either attached faster or more convenient. Take Note: 

     

“ammunition” means any unfired assembly of cartridge case, powder, primer and projectile which may be used in a firearm. Today, it refers to a “file of assembled cartridges” in bulks as in boxes or lots & also used to refer to the supply a person may be carrying with him. “round” refers to a single cartridge. shotgun cartridges are commonly referred to as “shell” or “shotshell” rifle ammunition is referred to as “metallics” or “cartridges”. When an investigator uses a term “cartridge” he invariably refers to revolver, pistol, or rifle cartridges. The layman uses the abovementioned terms indiscriminately, although as general rule he speaks of “cartridges” when referring to a pistol, revolver, rifle ammunitions and “shells” when referring to shotguns. Among the uniformed, the word “bullet” as often misused, as it is commonly used to apply to any sort of any unfired cartridge. Actually, it is that solid portion of the cartridge which leaves the muzzle of the gun and does the “striking” or “killing”. The word can properly be used in connection with pistol, revolver or rifle ammunition but other common designations for the bullet are “projectile” or “ball” is a relic of old muzzle- loading days when all rifle projectiles were round lead balls.

PARTS OF A CARTRIDGE (Nomenclature) 1. 2. 3. 4.

BULLET – the projectile propelled through the barrel of a firearm by means of expansive force of gases coming from burning gunpowder. CARTRIDGE CASE – the tubular metallic container for the gunpowder. Sometimes called ”shell” or “casting”. GUNPOWDER – It is the propellant which when ignited by the primer flash is converted to gas under high pressure and propels the bullet or shot charge through the barrel and on to the target. PRIMER – the metal cap containing the highly sensitive priming mixture of chemical compound, which when heat or struck by firing pin would ignite. Such action is called “percussion.”

CLASSIFICATION ACCORDING TO THE TYPE OF FIREARMS 1. 2. 3. 4.

Revolver cartridges Pistol cartridges Rifle cartridges Shotgun cartridges

CLASSIFICATION ACCORDING TO LOCATION OF PRIMERS 1.

2. 3.

4.

PIN FIRE CARTRIDGE – the first cartridge of a self –exploding type which enjoyed any real general use was the type called the “pin fire” commonly attributed to Monsier Le Facheux of Paris, around 1896. Pin-fire cartridges were made for all types was small arms in appearance to a modern shotgun shell wherein it had a head of the cartridge and a percussion fixed by a wad or metal cup. The percussion had a pin resting on its detonating compound. The end protruding of the e pin is hit by a hammer coming down vertically from the side of the cartridge instead of penetrating horizontally from its fear. This type of cartridge is no longer used. CENTER FIRE – priming powder is located at the center. RINGFIRE CARTRIDGE – A type of cartridge used only on sabotage cases. The chattel cartridges of Steyr advance combat rifle and Steyr anti-material squad machine gun. This is a special type of cartridge wherein the priming mixture is placed in a circular hollow ring about 1/3 of the base of the cartridge. RIM FIRE CARTRIDGE – The simplest form of modern cartridge is the “rim-fire cartridge”. The name “rim-fire” is derived from the fact that this type can be fired only if the cartridge is struck by the hammer of firing pin on the rim of he case. In this type, the priming mixture is contained or located in a cavity inside and around the rim of the cartridge which is a very sensitive area. If a rim fire cartridge is struck anywhere in the sensitive area, the priming substance is crushed between the front and rear of the case rim. This denotes or ignites the priming mixture, causing a flash of flame.

Rim-fire cartridges may be identified by the smooth base of the cartridge case, which may or may not have a head stamps are merely letters or design found on the base of the cases that identifies the manufacturer. These rim-fire cartridges are generally found in caliber .22s. They can be fired in either caliber .22 pistols, caliber 22. revolvers and caliber .22 rifles. Rim-fire cartridges can be further classified into: a. rimmed type – used in revolvers .38 and .357 b. semi-rimmed – used in super .380 c. rimless - .45 pistols, Thompson, grease gun, submachine guns TYPES ACCORDING TO CALIBER

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Caliber .22 – used in revolvers, pistols, rifles Caliber .25 – used in pistols and rifles Caliber .30 – used in carbines and other rifles Caliber .32 – used in automatic pistols and revolvers Caliber .380 – used in pistols Caliber .38 – used in revolvers Caliber .357 – used in .357 revolvers (Magnum) Caliber .44 – used in Magnum revolvers Caliber .45 – used in Automatic pistols Caliber .50 – used in caliber .50 machine guns

The abovementioned different classes of small arms cartridges are generally encountered by the Police in the field of firearms investigation in our jurisdiction. These are commonly used by criminals because they are used in firearms that are easy to carry, conceal, fire and dispose of. CLASSIFICATION OF AMMUNITIONS ACCORDING TO ITS EFFECTS 1. 2. 3.

Penetrators - pierce targets using a single bullet, High explosives - burst before hitting their target, fragmenting into thousands of penetrating pieces or becoming a high-speed jet of molten metal, and Carrier projectiles - break open near the target to deliver leaflets, radar-deceiving materials, or submunitions (small ammunition).

ARTILLERY AMMUNITION Artillery includes rocket launchers and such mounted guns as howitzers, mortars, antiaircraft guns, and naval guns. Most types of field and naval artillery ammunition are called shells. A single shell, like a single cartridge, is known as a round. Field artillery projectiles range in size from 50 to 240 millimeters and can weigh over 200 pounds (90 kilograms). Most artillery shells taper to the rear, a shape that gives them greater range. Some have streamlined ogives (nose shields). Others, known as base-burner shells, have a small amount of propellant burning in the tail during flight. This reduces drag (air resistance). Some shells are high explosives, which detonate on impact and damage or destroy the target. Detonating the shell's explosive filler shatters the shell into thousands of fragments. High explosives include TNT; RDX, also known as cyclonite or hexogen; composition B, a mixture of RDX and TNT; PETN; and pentolite, a combination of PETN and TNT. Other shells contain mines or small shells that can be expelled at intervals over a specified area or during a certain period of time. Still other shells are filled with a non-explosive substance, such as a chemical that is poisonous or that produces smoke or fire. Illuminating, or star, shells light up the battlefield or seascape. A shell with a chaff warhead expels strips of aluminum, which produce images on a radar screen similar to those caused by aircraft. Such images confuse radar operators and thus help protect aircraft from enemy attack. There are five main types of artillery shells 1. 2. 3.

Fixed ammunition fired by artillery consists of a projectile, a casing, a primer, and a propellant. Like small-arms cartridges, fixed artillery ammunition shells are manufactured as complete units. Semifixed ammunition resembles fixed ammunition. However, the projectile fits loosely into the casing so that the sections can be separated. Thus, the amount of propellant in the casing can be increased or decreased, depending on how far the shell is from the target. Separate loading ammunition, also called bag ammunition, consists of separate sections for the projectile, the primer, and the propellant. The propellant is packed into bags that are placed behind the projectile. The number of

4. 5.

bags used depends on the distance the shell must travel. This type of ammunition is used to fire the heaviest artillery shells over great distances. Separated ammunition consists of two sections. One section is the projectile. The other includes the primer, the casing, and a fixed amount of propellant. Guided ammunition can correct its flight in the air after being fired. It often uses pop-out tail fins to steer itself. Most guided ammunition finds its target by tracking a laser spot on the target. This spot is usually produced by a forward observer, a person or object forward of the line of fire. Some shells known as smart shells have small radars and computers in them. These shells can search for and find such targets as armored vehicles or trucks without help.

ARTILLERY-VEHICLE AMMUNITION Armored-vehicle ammunition consists of projectiles fired by guns mounted on tanks and other armored vehicles. They have diameters from 20 to 125 millimeters. A common armored-vehicle penetrator is a projectile with a nose cap of tungsten or another heavy metal. The cap helps the projectile penetrate opposing vehicles. A high explosive projectile is a hollow-charge warhead. This warhead is hollow in the front and has an explosive charge in the back. Its explosion converts a copper cone in the warhead to a molten, highspeed jet. The jet penetrates the target. Another armored vehicle projectile is a long dart made of tungsten or depleted uranium (uranium with most of its radioactivity removed). The dart travels on a device called a sabot, which breaks away after the dart leaves the gun's barrel. RIOT CONTROL AMMUNITION This is used by law enforcement officials to subdue rioters without causing serious injury. Most of this ammunition consists of hard rubber bullets. Another type is made of soft rubber rings that look like doughnuts and may contain tear gas. These rings cause less damage than do the rubber bullets. SHOTGUN CARTRIDGE (SHELL) Shotgun is a shoulder gun that fires a cartridge that contains a powder charge and a load of metal pellets, called shot. The shot spreads over a wide area. This makes it easier to hit a moving target with a shotgun than with the single bullet from a rifle or a pistol. The shotgun is chiefly a hunting gun. Kinds of Shots: 1. 2. 3.

bird shot - small shotgun pellets buckshot – larger ones are used to shoot such animals as deer single shot – consist of single unit of projectile

Shotgun cartridges consist of a plastic or paper tube with a brass or steel case at one end. They contain lead or steel shot instead of bullets. The caliber of a shotgun is measured by bore, or gauge. The weight of the lead shot required to fit the muzzle of the gun is the standard of measurement for the bore. If a bullet weighing 1/12 pound (38 grams) fits the bore, the shotgun is called a 12-bore, or a 12-gauge, gun. Popular gauges are 10, 12, 16, 20, 28, and .410. Some shotguns are named by caliber, as for example, the one that is called .410 gauge shotguns which actually means .41 caliber. A 12-gauge shotgun has a caliber of .729 inch. The first shotgun, developed in 1537, was loaded with small shot instead of one round ball. In 1831, Augustus Demondion patented a cartridge that held small shot. Modern shotguns are single barrels, double barrels, or single barrels with

automatic repeating magazines that hold several cartridges. Repeating shotguns are popular in the United States with hunters as well as with many law enforcement officers. SHOT WADS. At a distance of 5-8 yards or more from the place of firing in the approximate direction of fire, one can sometimes find wads. CARTRIDGE LIFE The life of well made metallic small arms ammunitions perhaps 10 years on the average. Some last 5-6 years, however, ammunitions may lose some of its strength in 5 or 6 years. Some may last 25 years or more depending on the conditions storage. Damp, and warm climates are worst. In order to prevent the entrance of oil or moisture, it is common practice to varnish the mouth of the case before the insertion of the bullet and to put a ring of waterproofing around the joint between the primer and the primer pocket. CARTRIDGE CASES/SHELL It is a tubular metallic or non-metallic container which holds together the bullet, gunpowder and primer. It is the portion of the cartridge that is automatically ejected from the automatic firearm during firing and this remains at the scene of the crime. This is firearm evidence that can help trace a particular firearm from which it was fired. FUNCTIONS OF CARTRIGE CASE The function of cartridge case is basically the same whether it is fired in revolvers, pistols, rifles, shotguns, or machine guns. These include: 1. 2. 3.

It holds the bullet, gunpowder and primer assembled into one unit. It serves as a waterproof container for the gunpowder. It prevents the escape of the gases to the rear as the sidewalls of the cartridge case are forced against the walls of the chamber by the pressure. It serves as a “gas seal” at the breech end of the barrel.

PARTS OF THE CARTRIDGE CASE 1. 2.

3.

4. 5.

RIM – the projecting rims of rimmed and semi-rimmed cases serve the purpose of limiting the forward travel of cartridges into their chambers and thus also limit the clearance, if any between the head and the supporting. PRIMER POCKET – performs three functions: a.) holding primers securely in certain position; b.) providing a means to prevent the escape of gas to the rear of the cartridge; c.) providing a primer support for primer anvils, without which the latter could not be fired. VENTS ORFLASH HOLES –the “vent” or “flash holes” is the hole in the web or bottom of the primer pocket through which the primer “flash” provides ignition to the powder charge. It is the “opening” or “canal” that connects the priming mixture with the gunpowder. THE HEAD AND BODY – the “head” and “body” constitute the “cork” that plugs the breech of the barrel against the escape of the gas. NECK – applied to that part of the cartridge case that is occupied by the bullet to prevent the bullet from being push back or loosened.

6.

CANNELURES – shell cannelures are the serrated grooves that are sometimes found rolled into the neck and body of cases at the location of the cases of the bullet to prevent the bullet from being pushed back or loosened. 7. CRIMP – is that part of the mouth of a case that is turned in upon the bullet. It works two ways a) it aids in holding the bullet in place; b) it offers resistance to the movement of the bullet out of the neck which affects the burning of gunpowder. 8. BASE - the bottom portion of the case which holds: a)the primer which contains the priming mixture; b) the shell head which contains the head stamp, caliber, and year of manufacture. 9. SHOULDER –that portion which supports the neck. 10. EXTRACTING GROOVE – the circular groove near the base of the case or shell designed for the automatic withdrawal of the case after each firing. CLASSIFICATION ACCORDING TO CASESHAPE 1. Straight – all rimmed shell and most centerfire revolver cartridges. Ex. Cal. 38 special 2. Tapered – very rare but being used in so-called “magnum jet” Cal. .22. 3. Bottleneck – ex. 5.56mm cartridge cases 4. Belted – ex. .30 magnum CLASSIFICATION ACCORDING TO HEAD FORMS 1. Rimmed – diameter of base is very much bigger than of the body 2. Semi-rimmed – diameter of base is slightly bigger than of the body 3. Rimless – diameter of base is the same as of the body CLASSIFICATION OF CARTRIDGE ACCORDING TO THE CONFIGURATION OF ITS BASE 1. RIMMED – It has a flange at the base which is larger than the diameter of the body of the cartridge case. This flange is to enable the cartridge to be extracted from the weapon in which it is used. 2. SEMI-RIMMED – It has a flange which is slightly larger than the diameter of the cartridge case and a groove around the case body just in front of the flange. 3. RIMLESS – The flange diameter is the same as the body and there is, for extraction purposes, a groove around the case-body in front of the flange. 4. REBATED – It has an extractor flange which is less than the diameter of the cartridge case. 5. BELTED CASE – It has a pronounced raised belt encircling the base of the cartridge, the belt is for additional strength in high pressure cartridge. CARTRIDGE CASES ACCORDING SHAPES 1. Straight cased – where the case diameter is approximately the same along its length. 2. Bottled-necked – where a wide bodied case is, just before the case mouth, reduced in diameter to that of the bullet. 3. Tapered case – where a wide based cartridge case is gradually reduced in diameter along its length. FUNCTIONS OF CARTRIDGE CASE 1. Serves as container for bullet, powder charge and the primer 2. Prevent the escape of gases 3. It serves as the waterproof container of the powder charge. Take Note: 

Annealing – is the process of making cartridge case by heating a brass to become very soft and ductile and very weak: when it is drawn or otherwise worked, it becomes hard, strong and elastic.

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Belted Cartridge – A cartridge, which has a raised belt before the extractor groove. The cartridge seats on this belt, most “Magnum” cartridge case. Also called a European type primer. Blank Cartridge – Is a cartridge consisting of the case with its primer, powder charge and a wad to train the powder. Blank Cartridge Pistol – A firearm without opening in the muzzle, the gas may escape through the hole in the top of the frame. Center Pin – serve us a locking device for the cylinder. Drawing – a machine operation in manufacturing cartridge cases. Is the process of making case by punching discs from a sheet of brass and then making these discs out into tubes closed to one end. Guard Cartridge – one loaded with buckshot or a reduced charge ball. Rolled Crimp – One in which the mouth of the cartridge case is turned inward into a cannelure on the bullet all around its circumference to retain the bullet at the proper seating depth. Round – One single complete cartridge. Ruptured Case – Any cartridge case, which has been split in firing so that the gas has escape. Short Cartridge – a metallic cartridge loaded with a small shot. Signal Cartridge – one containing vari-colored luminous balls of the “roman candle” variety.

BULLETS (Projectiles) Bullet is also knows as PROJECTILE – is a metallic or non-metallic body usually referred to as a bullet that is completely dependent upon an outside force for its power. Under this definition, the term may also include projectiles propelled from shotguns although strictly speaking these projectiles designed for shotguns are called “shot”, “slug” or pellets. In a layman’s viewpoint, a projectile fired from a firearms is called slug, although what be actually meant is a “bullet”. The term “bullet” originated from the French word “boulette”, a small ball. In common Police parlance, a bullet may be called “slug” which is a colloquial term. CLASSIFICATION OF BULLETS ACCORDING TO MECHANICAL CONSTRUCTION Basically there are two (2) kinds of bullets: 1. 2.

Lead Bullets – those which are made of lead or alloy of this metal such as lead, tin and antimony. Jacketed Bullets – those with a core of lead alloy covered a jacket of harder metal such as guiding metal and copper zinc.

Purposes of the jacket 1. 2.

keep the bullet intact and from not breaking up when it strike the target. prevent damage while in the weapon

3.

control expansion

Take Note:  

copper plated steel maybe used instead of gilding metal for the jacket of caliber .45 - jacket of metal patch made of cupro nickel or gilding metal. If jscket bullets are used in revolvers, the gun barrel will be loosened or destroyed.

TYPES OF BULLETS ACCORDING TO SHAPE 1. 2. 3. 4. 5. 6.

Pointed bullet Round Nose bullet Wad Cutter bullet Semi-Wad Cutter bullet Hollow Point bullet Boat Tailed bullet

* Another improvement in bullets was the boat-tail in which the name became .30 M1. The “M” stands for Mark but some contend stands for MODIFICATION. COMMON BULLET TYPES 1. solid lead point 2. solid hollow 3. solid paper patch 4. metal cased 5. soft point 6. metal cased hollow point 7. metal point 8. rifled slug 9. glycer type bullet 10. quadraximum PURPOSES OF BULLETS 1. 2. 3. 4.

.38 – disability purposes .45 – knocking power – subduing a maniac or amok M16 – fatal effects Garand and Carbine – penetration and long range shooting

TYPES OF BULLETS ACCORDING TO USE 1. 2. 3.

Ball Bullets – have a soft cores and are used against personnel. Armor Piercing Bullet – have hardened steel cores and are fired against vehicles, weapons and armored targets in general. Tracer Bullets – contains compound usually similar to barium nitrates which is set on fire when the bullet is projected. The flash of this smoke from this burning permits the flight of the bullet to be seen.

4. 5.

Incendiary Bullets – contains a mixture such as phosphorous or other materials, that can be set on fire by impact. They are used against target that will burn readily such as aircraft. Explosives Bullets – contains a high charge of high explosive and because of their small size it is difficult to make a fuse tat will work reliably in small arms ammunition. For this reason the use of high explosive bullets is usually limited to 20mm and above.

BULLETS’ MEASUREMENT (DIAMETER) Cartridges used in weapons other than shotguns are measured by caliber (the diameter of the bullet). Manufacturers and users of ammunition in the United States have traditionally specified caliber in decimal fractions of an inch. For example, a . 30-caliber cartridge has a diameter of 30/100 inch (7.6 millimeters). However, it is becoming customary to use millimeters instead. The U.S. armed forces specify caliber in millimeters. Small-arms cartridges are less than 20 millimeters or .78 caliber. EQUIVALENT OF CALIBER TO MILLIMETER 1. 2. 3. 4. 5. 6. 7.

Caliber .22 about 5.56 mm Caliber .25 about 6.35 mm Caliber .32 about 7.65 mm Caliber .30 about 7.63 mm (Mauser) Caliber .30 about 7.63 mm (Luger) Caliber .38 about 9mm Caliber .45 about 11.43 mm

CONVERSION TABLE 1. 2. 3. 4. 5. 6. 7.

cm to mm mm to inch inch to mm meter to yard grain to gram gram to grain gram to kg

-

Multiply 10.0 0.03937 25.4 1.094 0.06480 15.43 0.001

Take Note: .0002 second – explosion of a bullet by means of tremendous explosion of burning gases. Resistance of .38 is 15,000 to 45,000 ft./found. Buck-shot – it ranges 50 yards

  

Take Note: Ball Bullet – Bullets have soft lead cores inside a

 jacket. 

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Cannelure (bullet) – A knurled ring or serrated grooved around the body of the bullet which contains wax for lubrication in order to minimize friction during the passage of the bullet inside the bore. Dumdum Bullet – an out-moded and generally misused term – hollow point bullets manufactured in Dumdum, India.

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Explosive (Fragmentary) Bullets – Contain a high charge explosive, because of heir small size, it is difficult to make a fuse that will work reliably in small arms ammunitions. For this reason the use of high explosive bullets is usually to 20 mm. and above. Hollow Point – designed to increase expansion (sometimes called “express bullets”) Iced Bullets or solidified bullets – super cooled water made as a projectile. Lead Bullets - Actually a mixture of lead and one or more hardening ingredient. Metal Cased Bullet – colloquially used to indicate either a metal patched of full patched bullet. Metal Patched Bullet – any metal-jacketed bullet. Technically, it is a bullet having a metal cup over the base and extending forward over that portion of the bullet which bears against the rifling, the lead core being exposed at the nose of the bullet. Mushroom Bullet – colloquially. Any bullet designed to expand on impact. Technically, a metal patched bullet with exposed round nose. Ogive – the curved portion of the bullet that is symmetrical and forms the head of the projectile of ogival shape. Plated Bullet – a bullet covered with a thin coating of a copper alloy to prevent leading on the inside of the barrel. Pointed Bullet – more effective ballistically because there is less surface resistance to air, thus the speed is less retarded and greater velocity. Soft or Drop Shot – shotgun pellets made of ordinary soft lead made into round pellets. Soft Point Bullet – expands on striking hence it produces more serious damage and have greater stopping power: from a high velocity rifle, it will expand upon striking a flesh until it looks like a mushroom, hence, they are often called mushroom bullet. Such bullets are of little effect than a full-jacketed bullet in revolvers or automatic pistols, because the velocity is too low to cause the bullet to expand. Steel Jacketed Bullet – bullet having soft steel jacket, often clad or plated with gliding metal to prevent resting and reduce frictional resistance in the bore. Tracer Bullet – a bullet containing a substance inside the jacket at the base of the bullet which is ignited when fired showing a brilliant “tail light” during its flight. It has an incendiary effect if they strike before the “tail light” base burned put.

GUNPOWDER It is a substance or a mixture of substances which upon suitable ignition releases a large amount of chemical energy at a high and controllable rate, the energy liberation is to convert the propellant into a high of gas. CLASSIFICATION AND COMPOSITION Generally, there are two types of powder in small arms. These are: 1.

Black Powder (Europeans) – the standard ingredients are: Potassium nitrate 75%, Sulphur 10% and Charcoal 15%. It’s characteristics are: a. oldest propellant powder b. consist of irregular grains and have either a dull or shiny black surface c. produces grayish smoke and considerable residue is left in the barrel d. burns with reasonable great rapidity when ignited

Qualities (typical to all explosives) a. b. c. 2.

when ignited, it will burn by itself without aid from the outside air in burning, it gives off large amount of gas a considerable amount of heat is evolved Smokeless Powder – Nitrocellulose and Nitroglycerine as the major ingredients, mixed with one or more minor ingredients such as centralite, Vaseline esters, inorganic salts and etc.

CLASSIFICATION OF SMOKELESS POWDER 1. 2.

Single based (Nitrocellulose) – pure nitroglycerin gelatinized with nitrocellulose Double based - Nitrocellulose and Nitroglycerine with the following minor ingredients: a. centralite b. Vaseline phthalate esters c. Inorganic salt

Purposes of the minor ingredients: a. insure stability b. reduce flash or flame temperature c. improve ignitability Characteristics a. gray green to black in color and grains are similar in size and shape to the single-base propellants b. almost all have a perfectly definite shape such as: small squares; discs; flakes; stripes; pellets; and perforated cylindrical grains 3.

Triple based – Nitrocellulose, Nitroglycerine and Nitroguanadine - It was devised in an attempt to compromise between the low power single based powders and high power but excessive heat of double based powders. The percentage of nitroglycerin is small, but sufficient to give added power. The nitro-guanidine lowers the flame temperature while still adding active explosive constituent. One of its virtues is that it is entirely flashless though it does not generate rather more smoke than the other types.

4.

High ignition temperature propellant – Its main constituent is from RDX group of high explosives. It was moderated to the process of gelatinozation and was then developed by Dynamite Noble of Germany in conjunction with Heckler and Koch for the latter’s G11K2 rifle. This is a caseless cartridge.

Take Note: Cordite – A British propellant made by dissolving gun

 cotton and nitroglycerin and adding 5% of Vaseline. 

PRIMER

Gun Cotton – A very powerful explosive, like nitroglycerin which is a chemical compound and not a mixture. This is formed by the action of nitric and sulfuric acid on cotton or any other kind of cellulose.

It is an assembly which ignites the propellant. The primer assembly of center fire cartridges consists of a brass or guiding-metal cup that contains a primer composition pellet of sensitive explosive, a paper disc (foil), and a brass anvil. A blow from the firing pin of a small arms weapon on center of the primer cup compresses the primer composition violently between the cup and the anvil, thus causing the composition to explode. The hole or vent in the anvil allows the flame to pass through the primer vent in the cartridge case, thereby igniting the propellant. Rimfire ammunition, such as the caliber .22 cartridge does not contain primer assembly; the primer composition is spun into the rim of the cartridge case and the propellant is in intimate contact with the composition. In firing, the firing pin strikes the rim of the case and thus compresses the primer composition and initiates its explosion.

Take Note: 1807 – Alexander John Forsyth conceived the percussion ignition system. He was a Scotch Presbyterian Minister, chemist and hunter. First successful priming mixture was one composed of potassium chlorate. TYPES OF PRIMER ACCORDING TO ANVIL 1. 2.

Boxer primer (one flash hole) – favorite in U.S. invented by Col. Edward Munier Boxer in 1869. Berdan (European Type) – two flash holes or vents invented by Hiram Berdan of New York in 1850’s.

PARTS OF PRIMER AND FUNCTION 1. 2. 3.

4. 5.

Primer Cap – it is the soft guiding metal which serves as the container of priming mixture, paper disc and anvil. Priming Mixture – contains a small amount of explosive mixture which is sufficiently sensitive to result of chemical reaction being set up by the caused by a sudden blow. Paper Discs – this is made of thin shellacked paper disc that protects the priming mixture that will cause its disintegration. Its two-fold purposes: a. help hold the priming mixture in place and b. exclude moisture Anvil – it is made of spring tempered brass place inside the primer and it is on this side or point which the priming mixture is crushed. Battery Cap – battery cap as applied to shotgun primer serves as the main support for the whole primer components.

PRIMING COMPOUNDS 1. Corrosive – it has potassium chlorate – IF ignited produces potassium chloride which draws moisture from the air and this moisture speeds the rusting and corrosion in gun barrels. CORROSION – chemical wear and tear of the inside of the barrel due to rust formation or chemical reaction by products of combustion during firing.

EROSION – mechanical wear and tear of the inner surface of the gun barrel due to mechanical abrasion or sliding friction. 2.

Non-corrosive Mixture 25 yrs. ago: a. potassium chlorate (initiator & fuel) – 45% b. antimony (element & fuel) – 23% c. fulminate of mercury (initiator) – 32%

WWII – Frankford Arenal (FH 42) sulfur – 21.97% ; potassium chlorate – 47.20%; antimony sulfide – 30.83% Typical rimfire (Cal. .22) – Frankford Arsenal potassium chlorate – 41.43%; antimony sulfide – 9.53%; copper sulpho-cyanide – 4.70%; ground glass – 44.23% Germans fulminate of mercury – 39%; barium nitrate – 41%; antimony sulfide – 9%; picric acid – 5%; ground glass – 6% Swiss by Ziegler – 1911 fulminate of mercury – 40%; barium nitrate – 25%; antimony sulfide – 25%; barium carbonate – 6%; ground glass – 4% Take Note:  

Match Slow – a slow burning fuse or twisted cotton soaked in a solution of saltpeter or hemp or on matchlock weapons. Maynard Primer – another form of percussion cap. Explosive pellets were sealed at proper intervals between two strips of paper. This primer tape was then rolled and inserted in guns of suitable design. The action of cocking the hammer pulled the primer tape until a primer pellet lay under the hammer and over the ignition vent into the chamber ready for firing. Similar forms are used in cap pistols.

FORENSIC BALLISTICS (FIREARMS IDENTIFICATION) It is the study of recovered projectiles to identify the firearms which fired them. It would be better termed firearms identification. The evidence thus obtained is generally accepted in criminal Courts trials to establish use or possession of a certain weapon. Formerly, all that an “expert” could testify in Court concerning a bullet recovered from the scene of a crime was that it was a certain type and caliber. Thus a caliber .38 bullet could not have fired in a caliber .45 revolver. Linking a bullet to a specific revolver was not then possible. About 1920, great advances began to be made in identifying firearms by their fired bullets and/or cartridge cases, and for the first time, formed criminology courses were offered by universities to train individuals in the techniques of Forensic Ballistics. Colonel Calvin H. Goddard was the leader in this effort. The most important tools used was the Comparison Microscope, a binocular instrument so arranged that two similar objects can be compared in detail simultaneously, with corresponding surfaces adjacent. When bullet is fired, it acquires marks or scratches from the bore surfaces. These marks, from irregularities left by the tool cuts or caused by wear and rust, by reproducible by firing another bullet through the same barrel. The bullet is evidence and the second bullet can then be compared for match. The pattern obtain is comparable to a fingerprint, thus making coincidence of

identical patterns from two different guns most unlikely if not impossible. A composition is that, was yet, there has been no system devised to classify such patterns, as there is with fingerprints. When a cartridge is fired it is pressed forcibly against the breechface of the firearm, there receiving an impression of any tool marks. The firing pin also leaves its marks can be compared by the microscope, and a fired cartridge case thus be linked to a specific weapon.

ARMS MANUFACTURING PROCESS AND FIREARMS IDENTIFICATION How a firearm is manufactured? The first thing which is of importance for the Firearms Examiner is the understanding of the construction of a gun barrel and to be sufficiently familiar with the various steps in the manufacture of firearms which may influence the investigation of the crime. There should always be sound reason for all markings, scratches or dents visible or firearms evidence and it is the function of the firearms examiner to determine how and why they were made and also to interpret their significance both to himself as well as to the Court of Justice. The process of manufacture starts with a solid steel bar which, when drilled from end to end makes it is steel pipe. The interior surface at this stage bears numerous scratches resulting from irregular cutting of the drill and the metal chips which mark the finish. For smooth bore barrels, after the drilling process the inside of the barrel is made very smooth by a process known as “lapping”. In barrels intended for rifles the next steps after drilling consists of “reaming” and drilled hole for its entire length, this removes some of the sears and scratches. The reamer removes metal from the entire surface because it is slightly larger in diameter than the drill. If the barrel is to be rifled it is done with the use of modern tools which automatically cut the spiral grooves on the inside the barrel and impart to every firearms characteristics which are peculiar to the barrel. Each manufacturer has its own characteristics designed for the lands and grooves. It has its individual patterns which determine whether the grooves are inclined to the left or to the right. In addition to these peculiarities there are other markings left by the rifling tools which cuts the grooves that is as the rifling cutter wears small imperfections on its surface are transmitted to the surface of the barrel and in similar manner the accumulation of metal chips remove by the cutter will scratch the barrel as it passes along. Even in the button system imperfection will remain after the lapping and finishing operations are completed. These microscopic scars will make a series of striations on every bullet which passes through the barrel. It is the comparison of these bullet striations which is the basis of examination. Another phase of firearm manufacture which is of great importance to the identification of firearms is finishing operations of the breechface of the breechblock of the firearm. It is that portion of the firearm against which the cartridge is fired. TWO (2) GENERAL CHARACTERISTICS REGARDING FIREARMS IDENTIFICATION 1. CLASS CHARACTERISTICS – are those characteristics which are determinable even before the manufacture of the firearm. It is categorized into the following: a. b. c.

Caliber Number of Lands and Grooves Width of Lands and Grooves

d. e. f.

Twist of riflings Pitch of the rifling Depth of grooves

CLASS CHARACTERISTICS OF DIFFERENT FIREARMS a. b. c. d. e. f. g. h. i. j. k. l. m. n. o. p. q. r. s. t. u. v. w.

Colt Type ---------------------------------------- .45 6L G2X Grease Gun ------------------------------------- .45 6R G+ Smith and Wesson Rev. ---------------------- .45 6R GL Smith and Wesson Rev. ---------------------- .38 5R G=L Colt Revolver ---------------------------------- .38 6L G+ Colt Pistol Super-------------------------------- .38 6L G+ Colt Revolver ----------------------------------- .32 6L G+ Colt Pistol --------------------------------------- .32 6L G+ Colt Pistol --------------------------------------- .25 6L G2X Colt Revolver ----------------------------------- .22 6L G2X Colt Revolver ----------------------------------- .357 6L G2X Smith and Wesson Rev. ---------------------- .32 5R G=L Smith and Wesson MRF Rev. ---------------- .22 6R G=L Enfield Revolver -------------------------------- .38 7R G2X US Carbine -------------------------------------- .30 4R G3x Browning Pistol --------------------------------- 9mm 6R G=L Star Pistol ---------------------------------------- .380 6R G+ Llama Pistol ------------------------------------- .380 6L G+ Beretta Pistol ------------------------------------.32 6R G2X Astra Pistol -------------------------------------- .32 6R G2X Arminius Revolver ------------------------------ .22 6R G2X Burgo Revolver --------------------------------- .22 8R G+ Marlin M57 Rifle -------------------------------- .22 2OR G+

2. INDIVIDUAL CHARACTERISTICS – are those characteristics which are determinable only after the manufacture of the firearm. They are characteristics whose existence is beyond the control of man and which have a random distribution. Their existence in a firearm is brought about by the tools in their normal operation resulting through wear, tear, abuse, mutilations, corrosion, erosions and other fortuitous causes. These are the irregularities found on the inner surface of the barrel and on the breech face of the breechblock of the firearms as a result of the failure of the tool beyond the control of the manufacturer to make them smooth as a minor. PRINCIPLES GOVERNING FIREARMS EXAMINATION 1.

BULLET IDENTIFICATION a. b. c.

2.

No two barrels and microscopically identical as the surface of their bores all posses individual characteristics markings. When a bullet is fired from a rifled barrel, it becomes engraved by the riflings and this engraving on a bullet fired from one barrel will be different from that on a similar bullet fire from another barrel. And conversely,. The engraving on bullet from the same barrel will be the same. Every barrel leaves its “thumbmark” on every bullet which is fired through it, just as every breech face leaves its “thumbmark” on the base of the fired cartridge case.

IDENTIFICATION OF FIRED BULLETS AND CARTRIDGE CASES a. b.

The first thing to do in the examination of bullets is to conduct a visual examination of the bullets in order to familiarize with all markings appearing on it. Conduct examination of the bore of the firearm.

c. d. e.

Determine the conspicuous characteristics appearing on the bullet or any markings appearing therein. Markings appearing on the test bullet No. 1 and does not appear on the succeeding test bullet such markings should be disregarded. Consequently, such markings are called accidental markings which came from foreign substances. If the bullet is undersized or the bore of the firearms is badly worn out there will be a cylindrical passage of the expending gas will appear dark or black in the picture.

WHAT TO COMPARE? 1. 2.

Evidence Bullet Test/Standard Bullet Before proceeding in the examination of the firearm by means of the fired bullets, first identify the particular firearm through the class characteristics appearing on the cylindrical surface of the bullet. Manufacturers of firearms make certain marks which may distinguish firearms manufactured by them from that of other manufacturers. Each manufacturer makes specific number of spiral grooves and direction of the twist of rifling. A bullet recovered at the crime scene or from the body of the victim may show those marks and on examination, the examiner may presumptively state from what make of firearm it came from, thus, if one examination or recovered bullet, it was found out that there are six (6) grooves and the rifling marks are twisted to the left, then it is possible that it came from a Colt firearm. Smith and Wesson manufacturer has five (5) lands, five (5) grooves and with right hand twit of rifling. Other class characteristics varied from one manufacturer to another.

3.

SHELL Identification a. b. c.

The breechface and the striker of every single firearm leave microscopically individualities of their own. The firearm leaves its “fingerprint” or “thumbmark” on every cartridge which is fires. The whole principle of identification is based on the fact that since the breechface of every weapon must be individually distinct, the cartridge case which it fires is imprinted with this individuality. The imprints on all cartridges fired from the same weapon are the same and those cartridges fired from different weapon must always be different.

IMPORTANCE OF FIRED BULLET IN FIREARMS IDENTIFICATION a. By means of fire bullet you can determine the particular barrel of firearm used. b. Recovered bullet can tell the type, caliber and make of firearm from which it was fired. c. Can determine also the condition of the firearm us FIREARM CARTRIDGE CASE Before proceeding in the examination, conduct a preliminary examination on the cartridge case having a visual examination on the condition of such cartridge case. Determine whether or not it came from a revolver or from an automatic pistol and sub-machine guns. Examine those markings that are present on the base portion, the breechface marks, firing pin impression, the location of the extractor and ejector markings. Check also the markings caused by the chamber of the firearm. The magazine and the ejector port markings must also be taken into consideration particularly those cartridge cases from gums having full automatic mechanism. MARKINGS APPEARING ON A FIRED CARTRIDGE CASE 1. 2. 3. 4. 5.

Breechface marks Firing pin impression Ejector mark Extractor mark Chamber mark

TWO TYPES OF MARKINGS (individual) 1. 2.

Impression type – those markings caused by direct pressure contact. (ex. Breechface mark) Striated mark – those markings caused by sliding contact. (ex. Minute striations on the cylindrical surface of the bullet)

Take Note: 

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Abrasion (in the bore) – Scratches caused by using improper cleaning materials, or by firing ammunition with bullets to which abrasive material was adhering. Normal enlargement of the bore and wearing away of lands due to the abrasive action of the bullets. Accidental Characteristics - Those ate characteristics or marks left by some individual gun that occurred on that particular shot and may or may not reproduced on any other shots. For example, a grain of send of shaving of steel happened to be in the barrel when a shot was fired. Ballistician – Person whose knowledge in firearms identification is accepted by the courts and other investigation agencies. Definitive Proof – after the gun is finally completed, it is again fired with a heavy charge to ensure against accident. This is the definitive proof and guns passing this test are stamped with still another marked. Expert - As used in courts includes all witnesses whose opinions are admitted on grounds of specialized knowledge, training and experience. Fouling - The accumulated of a deposit within the bore of a firearm caused by solid by-products remaining after a cartridge of is fired. Heavy Rusting - Usually called corrosion rather than fouling. Proof Marks – It is the examination and testing of firearms by a recognized authority according to certain rules and stamped with a mark to indicate that they are safe for sale and used by the public. Provisional Proof – the testing of the rough gun barrels and fired with a heavy charge of powder to see if they are strong enough to be finished and assembled into gun. This provisional proof and a certain stamp are placed on barrels so tested. Secondary Firing Pin Impression – Is a mark on the side of the regular impression usually found in pistols. Shaving Marks – a shaving on the ogive portion of the fired bullet due to poor alignment of the cylinder with the barrel. This shaving is often found in the revolver. Skid Marks – When the bullet first starts forward without turning, that before the bullet can begin to turn, it moves forward a small distance and this makes the front of the groove in the bullet wider than the rear part. This skidding is more pronounced in revolvers. Slippage Marks – Scratches of the fired bullet due to badly worn rifling or when the bullet is small or too soft for the velocity used, there is a tendency for it to go straight forward without turning and it jumps the rifling or slips. Stripping Marks – scratches on the fired bullet due to worn out barrel.

TECHNIQUES OF EXAMINATION 1. Physical – Evidence bullets, cartridge cases and suspected firearm once submitted by the requesting party will be physically examined to determine its markings or initials made by the investigator for identification purposes. If no identifying marks were found the firearms examiner will, before anything, affix his own identifying markings or initials derived form the names of the requesting party, victim or suspect in that order of priority. The firearm will also be physically examine to determine its safety devices seeing to it that there is no cartridge inserted in the chamber that will cause accidental firing. Likewise, it will be examined of its vital parts whether or not it is in operating condition and a tag will be attached for distinction.

Bullets of different class characteristics will be segregated from one another especially the determination of caliber, number of lands and grooves, twist of rifling, etc. to facilitate its easy final microscopic examination. Cartridge cases will also be segregated to determine the caliber, type and make of firearm from which they were fired. Misfired or dud cartridges will also be taken into consideration. Although they may not have any ballistics probative value, yet, they may give a clue to the solution of a crime. 2. Test Firing – The firearm is test fired before a bullet recovery box in order to obtain test bullets and test cartridge cases for comparison with the evidence bullets and cartridge cases, respectively,. But before firing, the cartridge will be marked at the side of the case and on the nose portion of the bullet with letter “T” (to represent test) followed by the last two digits of the serial number of the firearm of the test to be made (eg) T-77-1 to T-77-3 in their order of firing to distinguish the number 1 test from the number 2 or 3 as the case may be. 3. Microscope Examination – After the recovery of the test bullets and cartridge case, they will be compared with the evidence cartridge cases under the Bullet Comparison Microscope to determine whether or not the have the congruency of striations or the same individual characteristics. BULLET COMPARISON MICROSCOPE Toady, the most widely and reliable instrument in Firearms Identification is the Bullet Comparison Microscope. With this instrument, the firearms examiner can make a complete examination and comparison of the so called Class and Individual characteristics that appears on the fired bullets and fired cartridge cases. This instrument consists of two single tubes fitted with a cross arm and comparison eyepiece, in which the images of two objects held on its two adjustable stages are fused into one, forming a single image as can be seen on the comparison eyepiece. The microscope tubes are built as a unit with the comparison eyepiece which has a prism arrangement that brings the images of the specimen held under the microscopic tubes into a side by side position in the left and right side of the eyepiece field the eyepiece is threaded for focusing on the dividing line between the two fields. Under the microscope the two fired bullets or fired cartridge cases can be examined in a “juxtaposition” and whatever the observation and findings obtained during the examination can be photographed for court presentation and also to give the Court a better understanding and good appreciation of how he came to that conclusion. HOW TO OPERATE THE MICROSCOPE Place the two objects on the two adjustable stages under the two microscopic tubes and peep through the comparison eyepiece. If the objects cannot be seen, adjust the stages through the rock and pinion mechanism. Once the two objects focused, the next step is to find the similarities existing between the objects either shifting them vertically or horizontally. Every examiner, no matter how experienced or expert he may be, has had the experience of spending many hours in the attempt to get the satisfactory and convincing matching in cases where there was every reason to believe that the has the gun that fired the evidence bullet or shell. Obtain matching as many as possible, because convincing one’s self and convincing the Court “beyond all reasonable doubt” are two quite different matters. Te expert must always keep in mind the fact, judges are always keep in mind the fact, judges are always unpredictable: if some pairs of grooves (or lands) match and others do not, the expert must be prepared to explain why they do not. FINDINGS/CONCLUSION Findings are the bases of conclusion. A conclusion cannot be made without the findings. A good conclusion is always based on good findings. In comparative examination of the evidence bullet that are found on the periphery running from the forward shoulder to the base portion (these are surface of the barrel), are discernible with the test bullet or if they have the congruency, correspondence or intermarriage, then the evidence bullet and the test bullet were fired from one and the same firearm. For conclusive of findings, there should be at least three (3) tests that should be compared. The first is for preliminary,

the second is for confirmation and the third is for conclusion. This is also true for fired cartridge cases. Although the individual characteristics of the cases may be found at the base portion where breechface, ejector, extractor markings are found on the sides that are in contact with the inner surface of the chamber. Clip or magazine markings may also give discernible markings. Like the ejector or extractor markings if considered singly may not be a basis for conclusion. These only serve as corroborative characteristics but certainly lack legal significance. This is so because the case may have these markings even if they were unloaded from the firearm without firing. As a rule, the point of the examination and comparison is at the area of the primer proper where breechface markings together with the firing pin impression are located. Primers are softer metals and receive more prominent striation than any other portion of the base. Conclusion is the opinion gathered from the finding. This is the end result of the examination and should be taken seriously as it involves the life and liberty of the suspect. When the evidence and the test bullets or cartridge cases have the same individual characteristics, the competent examiner will conclude that they were fired from one and the same individual characteristic; the competent examiner will conclude that they were fired from one and the same suspected firearm. If they have different individual characteristics, certainly, the evidence bullet or case was not fired from the suspected firearm. Where the evidence has prominent or minor striations that the three tests, it calls for uncertainty and doubt for a positive or negative conclusion. Only those evidence bullets or cases that have the same individual characteristics may be taken of photomicrograph for Court presentation. REQUIREMENTS FOR A POSITIVE IDENTIFICATION 1. 2. 3.

PROMINENT – Standing out or projecting beyond a surface or line, readily noticeable. CONSISTENT – Possessing firmness. The impression or striation found on the evidence bullet or cartridge case appearing in every test bullets and cartridge cases. SIGNIFICANT – The markings have meaning or capable of being interpreted by the Firearms Examiner or Ballistician.

INSTRUMENTS USED IN FORENSIC BALISTICS 1. 2. 3. 4.

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Analytical or Torsion Balance – Used for determining weights of bullets and shotgun pellets for possible determination of type, and make of firearm from which it was fired. Bullet Comparison Microscope – This valuable instrument is specially designed to permit the firearms examiner to determine the similarity and dissimilarity between two fired bullets or two fired shells, by simultaneously observing their magnified image in a single microscopic field. Bullet Recovery Box – Consist of a wooden box, 12 “x”12”x 96, with a hinged to cover and with one end open. This long box is filled with ordinary cotton and separated into sections by cardboard petitions. CP–6 Comparison Projector – An instrument very much similar with the bullet comparison microscope, where 2 fired bullets or shells can be compared in one setting of the firearms examiner. Also in one sitting, the evidence fired shell can b4e immediately compared with the test fired shell with the use of this equipment is absolutely no strain of any kind. No eye strain because the magnified image appears on a large screen and is observed as a vertical and comfortable viewing distance. No back strain from stooping over a microscope several hours a day. No mental strain because comparison of evidence is faster, easier and less tiresome, thus allowing a more efficient and productive of investigative time in the crime laboratory with method that can be seen in the screen can be photographed by any kind of camera. Filan Micrometer Eye Piece - a measuring microscope to read the width of the land and groove marks and to obtain the pitch of the rifling in turns per inch. Helixometer – Type of instrument used in measuring pitch of rifling firearms. This instrument is generally used in high advanced ballistic laboratory. It is not very much needed in a typical police ballistic laboratory. With the use of this instrument it is possible to measure the angel of twist in a rifle, pistol, or revolver barrel. It is used by the insertion of a telescope aligned with the axis of the bore. There is an eyepiece and an objective. The scope is mounted on a routable bearing with graduated discs that permits reading circular measurements, there is a scale graduated in inches. From the discs we can get the angel of the pitch, this can be combined with the scale reading to compute how many inches of barrel length would be needed for one complete turn of the rifling. Comparing this figure with those in tables of manufacturers’ specifications, we can often identify the making and the model of a weapon whose other features have been destroyed already. Machine Rest - A machine use for testing the accuracy of a firearm. Caliper – an instrument used for making measurements such as bullet diameter and bore diameter.

9. Micrometer – similar in use as caliber. 10. Onoscope – a small instrument sometimes used in examining the internal surface of the gun barrel in determining the irregularities inside the bore of the gun barrel. It has a tiny lamp at the terminal portion and this is inserted inside the bore for internal examination. 11. Optical Sight – sight containing series of lenses to form an optical system being contained in one unit. Optical sights do not necessarily have telescopic properties. The optical system may merely include range indicating, or range estimating devices, plus the necessary means of adjusting for elevation and wind age. 12. Shadow Graph – Equipment used in firearms identification. It contains a series of microscopic lenses of different magnification that can be used in examining fired bullet or fired shells to determine their class characteristics and also for orientation purposes. It greatly differs from the bullet comparison microscope and stereoscope microscope, that this instrument contains a large ground glass, 14 inches more or less in diameter, wherein the observation and comparison of the class characteristics is done by the firearm examiner. Similarly with the bullet comparison made in the circular ground glass. 13. Stereoscopic Microscope – unlike the bullet comparison microscope does not have any camera attachment and no photomicrograph can be taken for court presentation. It is generally used in the preliminary examination of fired bullets and fired shells to determine the relative distribution of the class characteristics or for so-called orientation purposes. It can be used also in the close-up examination of tempered serial numbers of firearms. It has two eyepieces and the lenses and objectives can be manipulated vertically with a series of magnifications. It is one effective instrument for firearms identification. 14. Taper Gauge – It is used primarily for determining bore diameter of firearms. This instrument is very useful for giving quick idea as to the caliber of a gun. 15. Telescope Sight – an optical employing the principle of the telescope to enlarge the image of the target. OTHER TERMS TO PONDER IN BALLISTICS 1. 2. 3. 4. 5.

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Accelerator – A device used in some automatic and semi-automatic weapons to accelerate the rearward travel of the bolt of breechblock by applying leverage at the critical point in the bolt’s travel. Any device of linkage designed to speed the movement of some portion of the mechanical train. ACP – Arms Corporation of the Philippines. Barrel Length - In interior ballistic work this differs from the "barrel length" use in general measurements. It is measured from the face of the muzzle to the base of the seated bullet or base of the case neck. Barrel Telescope – Instrument used to make a visual inspection of the inset of a gun barrel to see a sign of having been fired recently, to look for leading or metal fouling and to see how distinct the lands and grooves appear. Blow back – As pertains to automatic and semi-automatic arms, a weapon in which no mechanical locking system is employed. The breech is held closed at the moment of firing by the action of recoil springs and the weight of the slide, hammer and other moving parts. The weight of these parts is so much greater than the breech action has been appreciably overcome; then the breechblock action is blown backward, by residual pressure. A term commonly used to describe the backward escape of powder or primer gases from the chamber around the breechblock or bolt due to split or fractured cartridge case or punctured primer. Blow Forward – An automatic of semi-automatic firearm having a standing breech, in which the barrel is blown to open the action and eject the fired cartridge case. The barrel is then forced back against the standing breech by a powerful spring. The gun is cocked and reloaded as the barrel is forced to the rear. Bore Centerline - This is the visual line of the center of the bore. Since sights are mounted above the bore's centerline and since the bullet begins to drop when it leaves the muzzle the bore must be angled upwards in relation to the line of sight so that the bullet will strike where the sights point.

8. Breech Block – The steel block which closes the tear bore against the force of the charge; or the face of the block. 9. Burr Hammer – An expose hammer having a serrated knob at the top to provide a griping surface for cocking. 10. Camming – lug bolts – that type which employs one or more bolt locking logs which are cammed outward from the interior of the bolt cylinder to unlocked the action. 11. Chamber – the rear portion of the barrel where the cartridge is inserted. 12. Cylinder – serves as chamber and magazine and a revolver. 13. Cylinder Stop – stops and holds the cylinder in alignment for firing. 14. Delayed Blowback – Sometimes called hesitation locking the breech, although not positively locked, must overcome a mechanical disadvantage, such as knuckle joint, to open.

15. Disconnector – The lever in the gunlock which prevents the release of the hammer unless the slide and barrel are in forward position safely interlocked. 16. Double – Set Triggers – A pair of triggers so arranged that pressure on one trigger engages the sear in such fashion that the slightest tough on the second trigger will then discharge the gun. 17. Double Action Sear – Built into weapon to allow double action fire. 18. EC- Evansille Chrisler 19. Ejector - The mechanism in the firearm which causes the cartridge case or shell to be thrown out from the gun. 20. Extractor – That mechanism in a firearm by which the cartridge case or shell is withdrawn from the chamber mechanism in a revolver that pulls the empty shells simultaneously. 21. Extractor Rod – That mechanism in revolver that activates the extractor and is a locking device. 22. FA – Frankford Arsenal. 23. Falling Block Action –That type of action, which the breechblock is pivoted at the rear of the receiver so that the face of the breechblock swings down below the chamber to open the action. 24. FCC- Federal Cartridge Company 25. Firearm (Other Definition) - Means any pistol or revolver with a barrel les than 12 inches, any riffle with a barrel less than 15 inches, other weapon which is design to expel projectile buy the action of explosion.(Uniform firearms act of Pennsylvania) 26. Flying Firing Pin – A firing pin shorter that the length of its travel in the breechblock. A spiral spring coiled around the pin forward compressing the spring and exploding the primer, the compressed spring immediately draws the firing pin back into the breechblock. This is a safety feature since the firing pin is not in contact with the primer except when driven forward by the hammer at the instant of firing. Also known as rebound type firing pin Ex: Colt Government Model Caliber. 45 and Tokarev 7.62 mm. 27. Folding Trigger - A trigger hinged so that it can be folded forward close to under side of the frame. Ex: Italian 10:35 mm Bodego. 28. Frame - Part of the firearm that houses the internal parts. 29. Front sight - A protrusion or attachment above the barrel near the muzzle. It may be fixed or adjustable. 30. Grip or Automatic Safeties - Flat lavers of plungers normally protruding from some portion of the grip such position that when the hand firing the piece is squeezed around the grip, by the firer, automatically releasing the firing mechanism. In most cases, when pressure on the grip is relaxed the safety automatically resets itself, In a few instances, it must bee usually reset. 31. Hair Trigger – A term loosely applied to any trigger which can be release by very light pressure. 32. Hammer – mechanism in a firearm that strikes the prime. 33. Hammer Block - Safety device that prevents hammer blow to primer. 34. Hand (Pawl) - Mechanism of a revolver which rotate the cylinder. 35. Hanged Frame - A weapon in which the barrel including the cylinder in the case of revolver is pivoted to the forward end of the frame. Closing the gun swings the barrel into firing position where the chambers are firmly locked against the standing breech. 36. Headspace - The distance between the breech of the gun and the support for the cartridge rim; in other words, it is the space occupied by the head of the cartridge when the gun is loaded. 37. Head stamps - Merely the letters or design placed on the base of the cases by the manufacturer to identify his product. 38. Inertia Firing Pin - A firing pin assembled into the breech block and free to move forward and backward. It is impelled forward by the blow of the hammer or striker and backward by the explosions of the primer. 39. LC- Lake City Arsenal 40. Leaf Sight - Any metallic sight which is hinged at the base to permit raising it to a vertical position sighting and lowering it to a horizontal position to avoid damage and carrying leaf sight. Principle is usually applied to rear sight only. 41. Line of Sight - This is the visual line of the aligned sight path. Since sights are mounted above the bore's centerline and since the bullet begins to drop when it leaves the muzzle the bore must be angled upwards in relation to the line of sight so that the bullet will strike where the sights point. 42. Mainspring – mechanism in a firearm that provides energy to the hammer to activate firing mechanism. 43. Metallic Sights – normally consist of a pair of front sight and rear sights. 44. Muzzle Brake – a device attached to the muzzle of a gun designed to deflect the propelling gases emerging from the muzzle behind the bullet and to utilize the energy of these gases to pull the gun forward to counter the recoil of the weapon.

45. Open Sight – any sight in which there is to tube or aperture through which aim is taken. 46. Paradox Gun – a shotgun having the last few inches of the muzzle rifled so that it will impart a spin to the patented slug that is used with it when it is desired to fire a large single projectile instead of a charge of shot. 47. Parker size – a Gray rust preventive finish for metal. 48. Post Sight – A front sight resembling a post or one of generally rectangular of quadrilateral design. 49. Pump Action – Popular term for slide action. 50. Pyramidal Sight - a front sight of generally pyramidal design. 51. RA or REM – Remington arms company. 52. Ramp Sight – A front sight mounted at the ramp, which inclines upward and forward, a rear sight having a sliding member, which may be moved up and down a ramp to change the elevation of the sight. 53. Rear Sight – The rear-most of a pair of metallic gun sights. It may be mounted on the barrel, receiver, frame, slide, tang, cocking piece, bolt sleeve or stock; may be fixed or adjustable. 54. Receiver Sight – Any type of sight fastened to the receiver bridge. 55. Recoil Operated – Pertains to automatic and semi-automatic arms, a weapon in which the barrel and breechblock are locked together at the instant firing. As the bullet leaves the barrel, the rearward thrust of the powder gases starts the locked barrel and bolt to the rear. 56. Repeater – Any firearm holding more than one round at a time. 57. Rolling Block Action – that type of action in which the breechblock rotates its about an axis pin downward and backward from the chamber. 58. RPA – Republic of the Philippines Arsenal 59. Sear – The lever in the gunlock, which hold the hammer until the released by the trigger. 60. Semi-Automatic Revolver – are those in which the recoil from one shot plus spring action revolvers, the cylinder aligns a chamber and cocks the hammer ready for firing the next shot. 61. Set Trigger – An adjustable trigger design to operate reliable with a very light trigger pull. Colloquially a “hair trigger”. 62. Shoat Trigger – An absolute form of trigger in which no trigger guard was used. The trigger was mounted in and projected only slightly from the frame just forward of the grip. 63. Shoulder – Portion of a shell that support the neck. 64. Slide Action – That type of breech closure, which is moved forward and backward along guide ways paralleling the lower side of the barrel. The operating rod is properly linked to the breechblock to provide the desired and closing action. 65. Slide Plate – Part of the revolver that provides access to the internal part. 66. Signal Radius – the distance between forward and rear sight. 67. Silencer – A device intended to be attached to muzzle of a firearm to prevent or reduce its noise. 68. Single Action Revolvers – Are those in which the hammer must be manually cocked. 69. Solid Frame – in a revolver, a swing-out cylinder or rod ejector type. There is a break or hinge in the frame. 70. Spur Hammer – a hammer having a cocking spur. 71. Stab Crimp – a series of small indents at intervals around the cartridge case, engaging a cannelure in the bullet jacket. Both types of crimp are also used on high-pressure cartridge to hold the primer in the pocket. 72. Standing Breech – when a receiver is not cut away at its rear to a point below the line of the gun bore, the solid rear wall of the receiver is the “standing breech”. In the case of hinged frame weapons the solid rearward portion of the frame (receiver) against which the heads of the chambered cartridge rest after the gun has been closed and locked is the “standing breech”. In a revolver or single shot pistol that section of the frame that supports the head of the cartridge in the cylinder or chamber is the “standing breech”. 73. Straight-line Hammer – a metal forced straight back by bolt action during bolt reciprocation to cocked position. When released it drives straight ahead to fire. Found on reising and similar guns. 74. Straight-pull Action – that type in which the rotary motion required to turn the bolt locking lugs into or out of engagement with their locking recesses is applied by the action of studs on the bolt sliding in helical grooves cut inside a bolt cylinder. 75. Sub caliber Barrel – a barrel of small caliber inserted down the bore or mounted over the barrel of a large caliber gun, permitting it to be used for practice work with less powerful, cheaper ammunition. Generally, it is called a “Sub-caliber tube”. 76. Thumb latch – mechanism in a revolver that actuates bolt to release the cylinder. 77. Thumb trigger – a button design on or near the tang. It fines the rifle when depressed normally by thumb pressure. Tang-rear-ward projecting arms of the receiver into which the butt stocks is fastened. 78. Trigger – the lever operated by the shooter which releases the firing pin and allows it to discharge the cartridge.

79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90.

Trigger Guard – the bent strip of metal that protects the trigger from accidental discharge. Trigger Lever – mechanism in a revolver that contacts the rebound slide to return the trigger forward. Trigger Spring – spring that provides energy for return movement of rebound slide. Trigger Stop – mechanism in a revolver that prevents excessive rearward movement after hammer release. Tube Sight – a tube in which front and rear sights are mounted. Turn-bolt Action – that type of firearm which locked by the turning one or more bolt locking lugs into locking recesses cut into the receiver. U or UT – Utah Ordinance Company Vernier Sight – metallic sights which may be adjusted for elevation or wind age by the action of a vernier screw. Also called a micrometer sight. Screw having a head calibrated to indicate the amount of movement transmitted to the sight. WCC – Western Cartridge Company Wedge-type Bolts – that type which employs a ramp or camp arrangement raise lower, or move to either side, one end of the bolts so that the end of the bolt or lug thereon is wedged against a supporting surface in the receiver to lock the action. WRA – Winchester Repacking Company Yoke – mechanism in a revolver that connects pivot between the frame and cylinder.

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