Agree with Ray's observation about re-tightening the levers to the same position for repeatability of the zero. However, IME Ruger ring nuts infrequently, if ever, line up vertically when tightened. I use either small diameter SS or (preferably) brass shims as spacers between the nut and ring base to align the levers. The original levers from Brownell's included thin brass washers for this purpose and I've continued to use them in the new setup, with good success.

Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it Almighty God! I know not what course others may take, but as for me, give me liberty of give me death! P. Henry

Deus vult!

Rhodesians all now