shoot round the clock
Put a board out at say 25 yds and shoot a center spot,then wind up one full turn and shoot.
Then left, down a turn,down another then a full turn right.
Keep going round and up till you get back to zero[center spot],if the scope is tracking properly you should be back on zero and the other shots should be pretty even.
The optical center is a good pointer as too much turret adjustment can also make the mag ring very stiff.