Re: what is moa
With out over complicating the definition, from the shooters point of view, 1 moa is an angular measurment that starts centered at the rifle's muzzle and extends forever, when this angle reaches the target it will represent a certain distance. 1 moa is roughly 1" (actually 1.047") at 100 yards. Now the same 1 minute of angle @ 500 yards is roughly 5.0 inches for practical use, 5.235" more exactly. Simply put 1 MOA accuracy is generally reffered to as shooting under 1 inch per 100 yards of distance, like under 3 inches @ 300 yards.
Note: Just because you have a rifle capable of moa accuracy at 100 yards doesn't mean it will shoot under 10 inches at 1000 yards.