Ok the scope centering to the action is critical at long range!! The best way is to lap the rings, place the scope in the saddles after cleaning the git free. Next is to level the gun as best that you can, with the two lug action is pretty simple. Locate off the flats of the lugs with a piece that you know is flat, like a small machinist rule and level, sighting thru the scope at a plumb bob. This will get you pretty close. Take the rifle to the range, sight it in to shoot your scopes recommended shortest distance of focus at first. Then at 100 yards you will need a target that is 6 foot tall and a plumb bob hanging in front of the target. Shoot one shot at the center of the target, while keeping the vertical cross hair on the bullet hole, and the plumb bob string. Shoot the second shoot about an inch from the bottom of the target. Now here is where you are going to see the plumb of the vertical line, track the turret knob up (10MOA) keeping the crosshairs on the first and second shoots. Shoot once go up 10 more and shoot another, you will do this till you reach you most MOA you will be shooting. NOTE targets may need to be taller than 6 foot. You will find that the adjustment may be needed. If it does then hang a plumb bob over the target be sure not to move this target till this is finished, clamp the rifle in a sight vice. Line the vertical crosshair up with the bullet holes this is you rifle true level. loosen the ring screws not bumping the rifle around, line the crosshairs with the plumb bob tighten the screws and retest the steps to recheck. DONT SHOOT THE STRING. Scope centering tools are for short range 22lr.