If all bases and the actions they are mounted to were manufactured in perfect sync with each other, mounting a scope would be a piece of cake.
Unfortunately, the real world indicates otherwise.
Whether you go with a one-piece base or two-piece base, the odds are generally against you that they will be in perfect alignment. If you ignore this and tighten your new $500 scope in your unaligned rings, the result is that you will cause the scope tube to actually bend to match the misalignment of the scope rings.
This will put the inner workings of the scope in a bind.
Our lapping tool will help alleviate this problem.