I cannot put a scope on straight. Have some gadgets to do this with but still manage to screw up, just don't get the crosshairs straight up and down.
Recently I started getting the crosshairs perfect. I am using the Deadeye reticle leveling system and it work.
Simple, just place a small supplied level on the rifle, get it square in your vice or holder. Level is held in place with a large elastic band and is easy to position. Put it on the mount base, or bridge or even on the top of the turret if it is flat. Can't put the scope on square if the rifle is not square.
Then put the second part of the system, a variable vertical leveling rod out a short ways and line it up to plumb vertical with the bubble level that is built into the top.
Then line the scope up on the rod and tighten down the rings. Very simple system and results are perfect. I am a good person to test this out on as until now I had a hell of a time getting the crosshair vertical. This is a good fix. Check out:
www.deadeye2.com