Howland
Well-Known Member
I think scope manufacturers center the scope to the midpoint of vertical travel because they can't control how level the rails are in relation to the barrel. One minute of angle translates to just over one thousanth of an inch difference in height between the front and rear of a four inch rail or base. I mounted a scope on the rail of an M1A and I'm still about 3 inches high at 100 yards and I'm at the extreme end of vertical adjustment for the scope. The plus side is that puts me close to a 300 yard zero and I have the full vertical travel for elevation drop.