MOA WTF?

[Man of the Demoneye]

This may sound like a newbish question, but what exactly does MOA stand for? I figured that it was probably "minute of angle" but then I saw 2 MOA, 3MOA, etc. Using the same logic, I would guess that it would mean 2" and 3" groups, but why don't people just say that then? How close am I?  

[Tier One OPERATOR]

It is Minute of Arc/Angle. What it means, like you said, is 1MOA roughly equals a 1 inch group at 100 meters. More importantly, though, is that it can be extrapolated out to any effective range of a firearm. It provides a consistent measure of accuracy at any range, 3 MOA at 100m is as "tight" a group as 3 MOA at 800m.

It's a way to measure accuracy that doesn't depend on range.  

[Fresnel]

Horrified Survivor

It is Minute of Arc/Angle. What it means, like you said, is 1MOA roughly equals a 1 inch group at 100 meters.

2" at 200, 3" at 300...

Just thought it should be said.  

[Man of the Demoneye]

Okay, I haven't posted for a while because frankly, I was still a bit confused. I think I have it now. Thanks guys.  

[090Freak090]

more elaborately put 1 minute of angle is 1/60th of a degree (60 minutes in an hour, get it?) As you move out to 100yards it ends up being very close to one inch deviation for each 1/60th of a degree that the muzzle moves.  

[Requiem ex Inferni]

So correct me if I'm wrong, but does the MOA mean that ideally, there should be a space within one inch that the bullet should hit at 100 meters? Or am I completely off?  

[090Freak090]

Requiem in Mortis

So correct me if I'm wrong, but does the MOA mean that ideally, there should be a space within one inch that the bullet should hit at 100 meters? Or am I completely off?

1 MOA is one inch variance in the Point of Impact at 100 yards. So, based on the assumption that your rifle can provide accuracy 1 moa or less. However just because a rifle can provide 1 moa accuracy doesn;t mean that the shooter can shoot with 1 moa precision.  

[uryu ishida]

It's just a basic Angular Deviation dealio. I use a variant in my MOS, but it's called OF Factor. Multiply my angular readings (in Mils) by the factor to get the distance from one point to another. Multiply the MOA by the number of hundred meters!