MOA stands for Minute of Angle.
It measures about:
1" @ 100 yards
2" @ 200 yards
3" @ 300 yards
10" @ 1000 yards
And so on and so forth.
So if you have a 2" group at 100 yards then your rifle's accuracy is 2MOA (2/1 = 2) which by the way is not acceptable for long range work, but if you shoot a 2" group at 4" yards then your gun's accuracy is 1/2" MOA. (2/4 = 1/2)
One thing that I can tell you that will make your life easier is to think of the numbers of the scope turrets as MOA, not inches at 100 yards, this will simplify things for you.
By the way, Leupold charges about $60.00 for each turret, so it would run you about $120.00 to install target turrets on your scope.
Hope that helps.
-X3M
