Building The Steven's Favorite

[Highpower]

Darren, MOA = Minute of Angle. (Technically, minute of arc.)
A google search will explain it much better than I can.

In most discussions here in the states, MOA is roughly described as a spread of 1 inch per every 100 yards distance. So if all your shots hit inside a 1 inch diameter circle at 100 yards that = 1 MOA.
If they all fall within a half-inch diameter circle at 100 yards, that would equal 1/2 MOA.

2 inches @ 200 yards = 1 MOA
1 inch @ 200 yards = 1/2 MOA
3 inches @ 300 yards = 1 MOA
etc., etc.

Clear as mud?