If this is a A2 front sight, then 1 click of elevation change is equal to 1 1/4" at 100 yards.
You can tell the difference by looking at the front sight post. If the sides of the post are square, and if the base has only 4 cuts in it, it's an A2 sight. The cuts are where the detent rests. If the sight post is rounded, and the base has 5 cuts, then you have an A1 sight.
The A1 sight is a 1" per click at 100 yards adjustment.
Better to know this now rather than find out when you make dope changes at the 300 yard line!
I admit I stole this off another site. I thought I'd google my answer to check my recollection. Then I decided it was said quite well, and much easier to copy and paste here. The adjustments are for 20" barrels. I can't remember if Carbines get a little more movement of the bullet strick due to the shorter sight radius.
Test it out, shoot a 3-5 round group at 100yds, adjust a few clicks, shoot another 3-5 rd group. Take how far the new group moved from the old group, and divide by the clicks you adjusted, that's how far one click moves the round strike on your rifle.
