it appears u have external adjustment knobs. they're designed that way for a reason TO MAKE QUICK ADJUSTMENTS. dont hold over/under. initially zero at 25 yards, recording scope setting, then shooting at other distances (i recomend 50 yard incriments out to 1000 yards) providing for scope's adjustment limits. record the scope setting for each distance. leave setting at 100 yard zero returning there after each distance change. (make all adjustments from 100 yard zero.
zeros should be recorded for 1 particular load ( dont mix ammo). you can now engage targets at ANY distance within your selected range with reliable acuracy.