Shimming One Piece Scope Base

[Scragbait]

Hello

I have a problem with a one piece scope base mounted on a McLennan barrel. The rifle is a rebarrelled Ruger #1 and it looks as if the scope base was taken off the original rifle and placed on the McLennan barrel.

The problem is that the rifle shoots way too low at 25 meters and I've run out of elevation adjustment on the scope. The shots are about 10" too low with the elevation adjustment is maxed out.

I intend to shim the rear of the base to correct the alignment and get me back in the scope's elevation adjustment range. This would require about .020" in shimming at the rear.

Does anyone have any advice or insight on doing this? Are there alternative approaches to solving the problem? Are there good elevation adjustable rings to suit a target rifle?

Thanks.

 

[Moike]

I ran into a similar problem recently, trying to get enough adjustment out of a scope for 1 Kilometer shooting. I solved it by making a wedge out of “Devcon”, a steel impregnated epoxy material. I roughed up the bottom of the mount. I then attached a small metal shim the right height to the bottom of the mount with 10-minute epoxy and waited for it to dry. Its only job is to hold the shim in place until the Devcon sets. I taped off the receiver of the rifle out side of the mount size and covered the area with release compound. I use shoe polish and buff it off as a release agent, works better than anything else I have ever used. I put extra length screws (Brownells) into the receiver and cut the heads off them so the mount would have a guide and go on parallel to the axis of the bore. I “buttered up” the bottom of the mount with Devcon and laid it down so the bolts in the receiver went though the holes in the mount. I taped the mount down to the receiver and used Q-Tips to remove the excess Devcon that squeezes out between the receiver and base. I had to raise the rear of my base 60 thousands and it worked fine. I have fired over 500 rds to date and it has held up fine. As a precaution, cover the rifle with paper or plastic up to the tape, that Devcon seems to get on everything! My $0.02

 

[guntech]

Accuracy can be greatly affected by how well the scope mount is installed on a Number 1. It needs to be tight and stress free.. I would recommend altering the bottom of the front of the mount and then glass bedding the mount with the screws barely tight until it cures. The recoil pins should be drilled and installed last while the mount is in place...