Understanding MOA for Hunting
What is MOA?
You may have heard that a 1 MOA gun will shoot a 1 inch group at 100yds. While that is not false, that is also not completely true.
MOA is a measure of accuracy in guns and stands for minute of angle which is 1/60th of 1 degree. A lot of gun manufactures will guarantee their guns to be 1 MOA. This means that their gun will shoot within a 1 minute of angle cone from your point of aim. This happens to be within a 1 inch circle at 100 yards. 2 inches at 200 yards. 3 inches at 300 yards. And so on.
However, these 1 MOA rifles are likely guaranteed only in perfect conditions with match grade ammo and with the rifle on a shooting bench or vice, taking out nearly all shooter error. This means that your gun is 1 MOA only under perfect conditions—which is never the case when you’re hunting.
What Affects Accuracy?
Ammunition
The type of ammunition you use also plays a big role in accuracy and can affect your MOA. Typical match grade ammunition will make a gun shoot to its guaranteed MOA. This is because the amount of powder, burn rate, internal dimensions, and bullet seating depth are more consistent.
Bullet mass also plays a big role, and if you want to learn more about this, read an internal ballistics book. We don’t have time to discuss ALL of that in this blog.
If you’re not using match grade ammo, there’s an easy way to determine if your ammunition is impacting your accuracy. When ammo has inconsistent powder charges, one bullet may travel faster or slower than the next which will cause it to land higher or lower on the target. Therefore, if your groups are oblong (measured in height), you’re likely dealing with ammo inconsistencies affecting your accuracy.
Shooter Error
Shooting position, technique, and trigger pull can also affect accuracy. If your groups are oblong (measured in length), then it’s usually an issue with shooter inconsistencies like trigger pull.
Environment
The wind’s speed, direction, and angle can impact your accuracy since it can affect the trajectory of a bullet. Temperature and air density are also important factors which can affect ballistics. Finally, altitude affects accuracy because atmospheric pressure can alter air resistance.
Hunting MOA
Since hunting is never done in ideal conditions, your group sizes on a 1 MOA rifle will be larger than 1 inch when you’re hunting. While your gun is still technically shooting 1 MOA, all of the other factors impact your accuracy leading to larger group sizes. Therefore, it is important to account for this when you’re trying to determine if you’re able to make a shot.
Each shooter will add a certain degree of error to the gun’s acccuracy. For example, if you have a 1 MOA gun and your shooter inconsistencies like your trigger pull add 1/2 MOA, then at 100 yards, your shot will likely be in a 1.5 inch circle. And then, if your ammo adds another 1/2 MOA, you’ll be shooting 1.75 MOA. This means that at 200 yards you’ll be shooting 3.5 inch groups, and at 300 yards, you’ll be at 5.25 inch groups.
A more competent shooter will add less to their MOA than a new shooter, but even a good shooter will add some inaccuracies to their gun. A bad shooter could add 3 or more MOA.
In short, your 1 MOA gun won’t shoot 1 inch groups when you’re hunting. It is important, therefore, that you practice in non ideal situations so you know how much your MOA is affected and what shots you can and can’t make.