Applied Ballistics 10/9/2018
https://us8.campaign-archive.com/?u=85a26d49eeed45e81159c419f&id=9d2080b09eWe have all seen it. Either someone asks "Should I use MOA or Mils?" or incorrectly assumes that "MOA is Imperial Units (Yards) and Mils is Metric Units (Meters).†Well, the truth is neither: MOA or Mils are not units of distance at all. They are angular measurements. In this topic, I am going to break down the math and the basics of MOA vs Mils.
A Minute of Angle is 1/60th of 1 degree. A minute is 1/60th of anything you want it to be. There are 360 degrees in a circle, and there are 60 minutes per degree. This means there are 21,600 minutes in a complete circle. When we talk about a Minute of Angle we are talking about an angular measurement of 0.0166 degrees, which amounts to 1.047 inches at 100 yards or 1.141 inches at 100 meters. This is often why people associate MOA with Yards. Because at 100 yards 1 MOA is fairly close to 1 inch. Often people use what is called "Shooters MOA" where they will simply round to 1 inch.
A Mil, or (Milliradian/MRAD) is 1/1000th of a radian. A Radian is an angular unit equal to 57.3 degrees. For those math nerds out there (2π57.3 =359.99 or 360 degrees). So when we talk about Mils we are actually talking about 0.0573 degrees (which we’ll call MRAD). Similar to MOA above, some groups have different types of Mils as well, primarily to make the math easier for in-field calculations . You have the NATO Mils (1/6400th of a circle), Soviet Mils (1/6000th of a circle), Swedish Streck (1/6300th of a circle), Warsaw Pact Mils (1/6000th of a circle), USMC Mils (1/6283rd of a circle), and the true Mils or 6283.185th of a circle. The most commonly used in shooting sports is USMC mils as its the closest to true mils and the most accurate. 1 MRAD is 3.599 inches at 100 yards (1/10th is 0.36 inches), or 10cm at 100 meters. So you can see why it is pretty common to believe a MRAD is a metric unit of measure. 1/10th of a MRAD is exactly 1cm at 100 meters. Which is a lot cleaner than 0.36 inches at 100 yards when doing quick math.
Which one should you use? Well frankly the one that you are most comfortable with. There is no right or wrong answer here. (Actually there is: the one that you struggle the most with is the wrong answer.)
Which one is more precise? By numbers alone, the two are equivalent, but when it comes to their use in scopes, MOA is more precise than Mils. Scopes in MOA Form Factor can be had in both 1/4 MOA (0.26175" at 100 yards) and 1/8th MOA (0.130875" at 100 yards). Scopes in Mils can be had in 1/10th(0.36" at 100 yards) mil per click or 1/20th(0.18" at 100 yards) Mil per click.
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Simple Breakdown:
1 MOA @ 100 Yards = 1.047 Inches. (2.65938 cm)
1 MOA @ 100 Meters = 1.141 Inches. (2.89814 cm)
1 Mil @ 100 Yards = 3.6 Inches. (9.144 cm)
1 Mil @ 100 Meters = 3.937 Inches (9.999 cm)
We have 3.477 MOA per Mil.
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For conversion purposes:
Mils*3.477=MOA
MOA/3.477=Mils
(Generally it is ok to round to 3.5 for most shots)
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MOA and Mils are not Imperial and Metric units of measure. They are Angular Units of Measure which happen to work more nicely in one system vs the other.
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