I have a ruger 77MKII which was rebarreled. The scop I did have on it will not fit now 3x9x40 the scope bell almost touches the bbl. you can see a little daylight but a piece of paper will not pass under it. I was thinking of putting some copper shims inside the scope rings to get a little more clearance. or is there a way to shim the base itself ? My only other alternative is to buy a set of High ruger rings but I don' t want the line of sight anyhigher. So what to do ? I would like to do this ttonight so I can shoot tomorrow. ANY imput appreciated

358: coppper or brass shims will work but under the bases mounts not inside the rings

lonewolf is correct, don' t put the shims inside the rings, put them under the bases. In a pinch you can even use a piec of aluminum from a beer/soda can.

Never put any shimming material inside the scope rings. Not only will this screw up a good scope but also warp your scope rings. Remove the mount bases, place the shim under the bases, and reinstall.

IMO if you can see daylight between the scope objective bell and the barrel, then you are good to go. Only if they were touching would you have a problem. In other words .0001" is as good as a mile. I like my scopes to be as low as possible to the bore as the ring/scope/barrel combination will allow. BTW, a piece of paper is approximately .008" thick.