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What is the definition for Minute of Angle? I have always read about rifle accuracy and sub MOA groupings but have never understood what this really means.
 

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I'm sure others can explain it better than me.

But, basicly 1 MOA is holding accuracy of 1/2" at 50 yards, 1" at 100 yards, 2" at 200 yards, so on and so forth.

If you hear the term sub moa. That means the rifle is capable of groupings of less than 1" at 100 yards. Such as 3/4 moa would be groups of 3/4" at 100 yards.
 

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A circle is divided into 360 degrees and each degree is dived in 60 minutes and each minute is divided into 60 seconds. At 100 yard, 1 degree covers 62.82 inches and one minute covers 1.047 inches.
For most things Moa accuracy is a group that measures 1 inch from center to center of the furtherest apart shots. Sub Moa groups would be less than 1 inch center to center. Most folks round off the 1.047 inches to a even 1 inch.
 

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GunDoc is correct on that as always. I was gonna get one of my reloading books to pull the definition but don't have to now. Your part way there to understanding ballistics. Now all you have to do is understand drop and hold over, allow for the windage and you'll be as confused as the rest of us....LOL
 

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Hunters are still in the moa category of shooting. Benchrest is chasing 1 soa accuracy. 1 second of angle @ 100 yds = .01745 inch or .0349 inch @ 200 yds. Both of those group sizes have been achieved in competition. The benchresters still measure in rounded off moa, but their groups are getting down into true 1 soa neighborhood.
 

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Okay Gundoctor, I'm really confused now. 360 degrees are measured from the center of a circle. When you get to the edge of a circle the spacing of the degree angles would be farther apart, so a wider group at the edge of a target could be a moa group? by the same token, a group in the bullseye would have to be in the same hole to be moa? I have always measured groups by the distance of the farthest apart shots. By using this theory it seems like you could put a shot in the bullseye,put another shot 6 inches away, and another shot off the target and as long as they line up in a straight line it would be a smoa group. I must be missing something.
 

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Pretend your looking at a compass, its divided into degrees. Each degree has 60 minutes. Each one is a division of the next. Now read GunDoc's post again and see if it makes sense. The way to measure your groups is to measure to 2 most extreme points(outer edges) in the group and subtract your caliber. So if your shooting a 30 caliber weapon and your group measures right at one inch, you'd have a grouping that measured .70 or about 3/4 MOA. At 100 yds, MOA is one inch, 200 yds MOA is 2 inches......at 500 yds MOA would be 5 inches and so on. SOA is MOA divided by 60. This just measures your spread from taking multiple shots, doesn't necessarily account for where the bullseye is on paper. These are usually 3 or 5 shot groupings.
 

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You need to think of it as a cone starting from the end of your gun barrel and getting ever larger the further away your target is.

1/2" MOA = 3 or 5 shot groups measuring from the furthest outside impacts at the following distances- 1/4" @ 50yds., 1/2" @ 100yds., 1" @ 200yds., 1 1/2" @ 300yds.

1" MOA = 3 or 5 shot groups measuring from the furthest outside impacts at the following distances- 1/2" @ 50yds., 1" @ 100yds., 2" @ 200yds., 3" @ 300yds.

2" MOA = 3 or 5 shot groups measuring from the furthest outside impacts at the following distances- 1" @ 50yds., 2" @ 100yds., 4" @ 200yds., 6" @ 300yds.

5" MOA = 3 or 5 shot groups measuring from the furthest outside impacts at the following distances- 2 1/2" @ 50yds., 5" @ 100yds., 10" @ 200yds., 15" @ 300yds.

10" MOA = 3 or 5 shot groups measuring from the furthest outside impacts at the following distances- 5" @ 50yds., 10" @ 100yds., 20" @ 200yds., 30" @ 300yds.
 

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MOA can be misleading, too

Just because your rifle will shoot a 1/2" at 100 yards doesn't necessarily mean it will shoot 1" at 200 yards. Groups tend to open up exponentially as range increases from what I've seen. Bullet selection, velocity, barrel selection, and even the caliber of the rifle will affect long-range precision. My Rem 700 30-06 has a best group of 0.156 MOA at 100 yards, but my best 200 yard group is around 1 inch. I'm still working on loads to get this better.
 

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nasakid said:
Just because your rifle will shoot a 1/2" at 100 yards doesn't necessarily mean it will shoot 1" at 200 yards. Groups tend to open up exponentially as range increases from what I've seen. Bullet selection, velocity, barrel selection, and even the caliber of the rifle will affect long-range precision. My Rem 700 30-06 has a best group of 0.156 MOA at 100 yards, but my best 200 yard group is around 1 inch. I'm still working on loads to get this better.
That's true, but you are moving into projectile ballistics and possibly wind drift.

What I posted is just a table that crosses measurement of groups at different yardages and correlates them to MOA nomeclature.

It certainly doesn't mean you can shoot a 1/4" group at 100yds. And then instantly think you can easily shoot groups measuring 2 1/2" @ 1000yds. But they would both considered 1/4"MOA.
 

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gundoctor said:
Hunters are still in the moa category...
I'd be happy with mob as a hunter. Minute Of Bambi...hahaha...roughly 3" at 100 yds.

Of course as a plinker I'm not satisfied with anything over 1 moa.
 
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