I've got a problem with a gun I recently had built. It started as a 700 ltr. I had a Leupold 6.5-20 mounted in Talley steel rings. The gun shot very well, but I wasn't satisfied with the .308, so I parted out the barrel and stock and used the action to have a rifle built. I now have a scope mounting problem. My scope mounting screws do not appear to be aligned with the bore. Before the build, I had left and right windage adjustment. Now I don't. I would like to use my Talley rings and bases, but I run out of windage adjustment. I've shot the rifle around 50 times while sighting in and it appears to group well, but I haven't tried to ring it out until I can get my scope aligned with the bore an take advantage of my windage adjustment. I've tried three scopes and run out of windage adjustment. I don't want to use leupold bases with windage adjustmentn screw, but I may be forced to do so. How hard is it to drill and tap the receiver to align the bases with the bore? What about Burris Signature rings with the plastic inserts, do the inserts shift poa as much as they claim?