Once you get your action level you need to get your vertical crosshair perfectly vertical. I put my rifle in my long-range rest setup then while the rifle is level I line the vertical along a house 100 yds away then tighten the rings to hold the scope. Then I rotate the level around the scope to match the B-Square level on the Picatinny rail. Then test fire at 200 yds on a 30" white paper with a perfectly vertical line from top to bottom. If your rifle hits the line from top to bottom while turning the elevation turret your equipment it correct.
This system has worked for me every time I did it. At 1,000 yds I only have to adjust the windage turret for the spin of the bullet and wind.
that makes sense about raising the turret adjustment and watch to see if the cross hair stays on the line. The key to that process is to have the gun mounted in a solid vise or something that wont let your gun move at all as you adjust the turret. I will double check that.