There's no good way IMO, somethings always off with level bubbles etc...I don't think knobs are 100% inline with crosshairs.

Gotta eyeball it, check, adjust, recheck, etc...

also remember as you screw down your rings that action will sometimes twist your crosshairs, so try to screw em down evenly on each side.

good luck!

find a straight line on the wall...tile, corner, etc that should be a straight line...thats what i did with my latest mount job and it worked...

i used the tile on my shower walls...i watched the guy put the tile in and he was pretty meticulous about it..so i trusted that the grout lines were going to be straight...and it gave me vertical and horizontal lines to line up the scope...


if i eyeball it without a straight line, mine are always crooked..must be the way i hold my head on the gun as they look straight to me...and i dont notice till someone else tells me...then i'll notice they are ever so slightly crooked slightly clock wise...