What's with that name? And what the heck is a MOA?

Thanks for asking, MOA – short for “Minute of Angle” – it is an angular measurement. A MOA is 1/60th of 1 degree of angle. We all remember from school that a complete circle is 360 degrees, and as we dig a little deeper we find that each of those “degrees” has 60 “minutes” of angle within it. So, you have 21600 (360x60) minutes of angle (or arc) in a circle. “MOA” is a common term among some hunters and target shooters when talking about the performance (accuracy) of a gun. It is also a very common term used to make adjustment to sighting scope used on a gun. Most hunting scopes and many target scopes have adjustments in increments of ¼ or ½ MOA.

OK I got that, but how much are we talking about in “real numbers”? Alright, think about if you had a string that was 100 yards long, and one end of the string is tied to a table where you were sitting (point A). The other end of the string is pinned to the center of a large upright pizza box lid (point B) 100 yards away. Now if we were to move the pin in the pizza box any direction (right, left, up or down) by 1.047 inches, we would have moved it “1 MOA”. We will save the math (trigonometry) for another day. So 1 MOA at 100 yards is 1.047 inches, and 2 MOA at 100 yards would be 2.094 inches (2 times 1.047).

Now back to our rifles, let’s replace the table that you are sitting at with your bench rest and gun and we will replace the “pinned” places in pizza box lid with bullet holes. If you had 2 bullet holes that were LESS than 1.047 inches apart from the each other that would be LESS than a MOA or “subMOA” hence the name. Of course, as the distance is extended from the rifle to the target (100 yards in our example) the distance between the bullet holes can expand accordingly and remain sub MOA. At 200 yards 1 MOA is equal to 2.094”, at 250 yards 1 MOA is 2.618” (2.5 times 1.047”). Most rifle group comparisons are based on more than 2 shots, 3 and 5 shot groups are more common.

The NSSF (National Sporting Sports Foundation) has produced a great video, Ryan Cleckner (former Sniper Instructor) does an excellent job of explaining what an MOA is in this video. (it’s about 16 minutes in length) Understanding Minute of Angle (MOA).

sub means "under" , "below" or "less than" so subMOA is less than a MOA.

As Always, Be Safe and stay tuned,

Wally

subMOAshooting.com