I agree with Waptirod about the reamer being a better choice. Both Clymer and Manson make quality scope reamers. If you have ever seen a scope with linear scars on its sides, it came from rings that were uneven. The older Ruger factory rings and SAKO rings were notorious for scarring scopes because of poor fit. Tightening down the rings would drive the sharp inside edges of the rings against the scope, and the scarring would be caused because the sharp edge was the only thing touching the scope. In addition to reaming horizontal rings, I take a fine file and knock off the sharp inner edges of the rings. Makes for a more secure fit with both old and new scopes/rings.