Thanks to all for the suggestions. I will try the rear screws first. I will seek professional help on the dovetail as the front base looks to be in there pretty tight. I tried some ammo loaded by Hornady for Graf and Sons. It uses a 140 grain Hornady bullet. This load shoots only slightly to the right, but is not as accurate or "traditional" as the Lapua. I went with that bullet as the 160 Hornady RN I used in a single shot 6X53R is not available anymore.