Mil Dot Guide

Ball-MilDot guide:Layout 1

6/9/08

10:29 AM

Page 1

EXAMPLE: FROM 100 YARDS AND WORKING UP Target size One Mil = 3.6” 7.2” 10.8” 14.4” 18”

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Target size

Yards to the Target 100 yards 200 yards 300 yards 400 yards 500 yards

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21.6” 25.2” 28.8” 32.4” 36”

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Yards to the Target 600 yards 700 yards 800 yards 900 yards 1000 yards

1 mil

Mils

Mils

Mils

Mils

Mils

Mils

Mils

100 yards

2.5

3.33

3.89

4.44

5.00

6.67

10.00

200 yards

1.25

1.67

1.94

2.22

2.50

3.33

5.00

300 yards

0.83

1.11

1.30

1.48

1.67

2.22

3.33

400 yards

0.63

0.83

0.97

1.11

1.25

1.67

2.50

500 yards

0.5

0.67

0.78

0.89

1.00

1.33

2.00

600 yards

0.42

0.56

0.65

0.74

0.83

1.11

1.67

700 yards

0.36

0.48

0.56

0.63

0.71

0.95

1.43

800 yards

0.31

0.42

0.49

0.56

0.63

0.83

1.25

900 yards

0.28

0.37

0.43

0.49

0.56

0.74

1.11

1000 yards 0.25

0.33

0.39

0.44

0.5

0.67

1.00

Congratulations on choosing a premium riflescope that contains one of the most precise but least understood aiming systems ever made - The Mil-Dot reticle. “Mil” does not stand for “Military”. Rather, it stands for milliradian which is a proportional measurement. A Mil means 1/1000 of any distance you measured. The most common example is one Mil equals 1 yard at 1000 yards.

Unlike other reticles, the Mil-Dot system will allow you to compute not only your range-to-target, but also hold over/under for ballistic compensation and windage compensation.

What is a Mil-Dot? There are a few technical facts about the Mil-Dot reticle that you need to understand.

EXAMPLE: FROM 1000 YARDS AND WORKING DOWN Target size One Mil = ©2006 Burris Company, 331 East 8th Street, Greeley, CO, 80631

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MIL-DOT Riflescopes

1. One Mil = 1 yard (36”) at 1,000 yards or any mathematical component of this base figure. For example, one Mil equals 3.6’’ at 100 yards, 7.2” at 200 yards, 14.4” at 400 yards and so on.

1 mil

1/4 mil

approximate examples Size of Avg Large Bull Bull Object Fox Coyote Antelope Deer Deer Elk Cattle Being 9" 12" 14" 16" 18" 24" 36" Measured (.25 yard) (.33 yard) (.39 yard) (.44 yard) (.5 yard) (.67 yard) (1.0 yard)

1 mil

5. The distance from the center of the crosshair to the edge of the “fat” part of the crosshair is 5 Mils.

Mil-Equivalent of Inches or Yards at Various Yardages

5 mils

4. The distance from the center of the crosshair to the center of the first Mil-Dot is also one Mil. The distance from the edge of the “fat” part of the crosshair to the center of the closest dot is also one Mil.

1 mil

3. The distance from center to center of each Mil-Dot is one mil. The thickness of one Mil-Dot is 1/4 Mil and the distance between Mil-Dots is 3/4 Mil, therefore the distance from the top of one dot to the top of another dot is also one Mil.

3/4 mil

2. Mil-Dots in a Burris scope represent 1 Mil only when your scope is set on it’s highest power setting--for example at nine power on a 3X-9X. The exception is the 8X-32X scope or scopes with a Ballistic Mil-Dot™, both of which needs to be set at the power ring calibration mark at roughly 14X-16X for proper measuring.

Table 2

6

INSTR-1011

36” 18” 9” 4.5”

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Yards to the Target

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1000 yards 500 yards 250 yards 125 yards

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Ball-MilDot guide:Layout 1

6/9/08

10:29 AM

Measuring Distance: Tables: So, based upon what you’ve read so far, measuring distances should be fairly simple. Take a look at Table 2. Let’s take a Mule Deer as an example. Lets say that the average distance from shoulder to brisket on a large buck mule deer is about 18", or 2.5 Mils at 200 yards as illustrated below:

Page 2

Ballistic Compensation: The key to calculating ballistic compensation is understanding your shooting system. Each barrel length, caliber and ammunition combination is unique. All of these factors, as well as the altitude and environmental conditions, effect external ballistics. So, a simple series of charts lends limited help and poses a dilemma. How can you create a chart that is custom tailored for your specific rifle and ammunition. The best way is to fire test groups at specific distances, under expected field conditions so as to you create your own customized chart.

Another good example would be a standing prairie dog. At 9" tall, it would span 1 1/4 Mils at 200 yards or 1/2 Mil at 500 yards.

Formulas: Tables are great for easy of use and usually gets you “close enough” to make a clean shot. If you want even greater precision, here are a couple of handy formulas which you can use to calculate distances. You may want to take a pencil and paper into the field, or better yet, a hand held calculator or watch calculator. Object’s Height or Width in Yards x 1000 = Target’s Measured Height or Width in Mils

Object’s Height or Width in inches x 27.77 = Target’s Measured Height or Width in Mils

Range in Yards

Range in Yards

To calculate how much (in Mils) you must “hold over”, (or under), you simply switch around the equation:

Now translate the trajectory and/or wind drift information on to your reticle and hold over or under the target. By using this method, you will be able to accurrately engage your target without adjusting the zero of your rifle scope. Below, and on the reverse, are a couple of tables that can help you to use the Mil-Dot without using formulas and calculators to estimate the distance to the target. Good luck and good shooting!

Table 1

If this is not practical, there is are numerous sources that publish bullet trajectory and wind drift data that will get you very close. If you’re using factory produced ammunition, obtain the information from the manufacturer.

Inch-Equivalent of Mils at Various Yardages

If you’re hand loading, most bullet, and powder manufacturers provide external ballistic information in their handloading manuals. You need to base your calculations on the velocity of your load and the bullet’s ballistic coefficient.

100 yards

0.9"

2.7"

3.6"

7.2"

10.8" 14.4"

200 yards

1.8"

5.4"

7.2"

14.4"

21.6" 28.8"

36"

300 yards

2.7"

8.1"

10.8" 21.6"

32.4" 43.2"

54"

Once you have the basic information, you can create your own MIL-DOT CHART listing trajectory and wind drift information for your rifle/ammunition combination. A sample of this would look something like:

400 yards

3.6"

10.8"

14.4" 28.8"

43.2" 57.6"

500 yards

4.5"

13.5"

600 yards

5.4"

16.2"

21.6" 43.2"

64.8" 86.4"

108"

700 yards

6.3"

18.9"

25.2" 50.4"

75.6" 100.8"

126"

308 Win168gr, 2700fps,.447 Ballistic Coefficient

800 yards

7.2"

21.6"

28.8" 57.6"

86.4" 115.2"

144"

900 yards

8.1"

24.3"

32.4" 64.8"

97.2" 129.6"

162"

108"

180"

Dist. (yards.) Mil 100 - .55 200 0.00 300 + .79 400 +1.72

Drop Inches +2.0” 0.0” -8.6” -24.8”

Mil .19 .43 .69 .95

10 MPH Drift .7” 3.1” 7.5” 13.7”

1/4 Mil = 3/4 Mil = 1 Mil = 2 Mil = 3 Mil = 4 Mil = Inches Inches Inches Inches Inches Inches

1000 yards 9"

27"

18"

36"

36"

72"

Bullet Drop at the Target in inches x 27.77 = Hold Over in Mils Range in Yards

3

4

5

54"

72"

144"

5 Mil = Inches

18"

72" 90"