The only way I know to align the rings on Weaver style bases is to use thin shims. You pretty much hope that the holes are drilled straight and every thing lines up right. That' s why I do not use them.

Brownells sells great little scope allignment bars if you want to buy a real set. They have been machined to a point so that you can be very accurate with your rings.

http://www.brownells.com/aspx/NS/sto...DS&s=3147#3147