The cheapest way to fix the problem is to get a set of Burris Signature Pos-Align rings with the concentric inserts. They work very well and are pretty inexpensive. I have used several XTR rings and have never had a problem with them. Do not lap aluminum rings, it will take the hard anodizing off and the rings will leave marks on the scope. Also, make sure you are torquing the ring caps and cross bolts properly or your scope can move in the rings. Burris XTR rings should be torqued to 20-25 inch pounds on the caps and 60-100 inch pounds on the cross bolts. The caps on the Signature rings should also be torqued to 20-25 inch pounds.