What is the right way to shim a scope? Trying to put zero in the middle of the scopes adjustment range, to allow more room to go from chickens to rams. I have used shims under the rear of the scope for years, but it can lead to the scope being marked up. I understand that it is not the most correct way to do it, but I also don't know what is. I thought shimming the base and then either glassing the rings or lapping the rings would allow for more scope to ring contact, but I can't find any smiths that will do it. What do you advise?

I can't say what the "right" way is. I've always used heavy plastic (like from a milk jug) for a shim when needed and have not had any problems with marring the scope up.

If you can spare the weight, the Burris Signature rings come with spherical insets that self-align and will not mar the tube. You can get various offset inserts to shim for elevation or even windage if you turn them sideways.

acorneau wrote: ↑Mon Dec 04, 2023 10:16 am I can't say what the "right" way is. I've always used heavy plastic (like from a milk jug) for a shim when needed and have not had any problems with marring the scope up.

If you can spare the weight, the Burris Signature rings come with spherical insets that self-align and will not mar the tube. You can get various offset inserts to shim for elevation or even windage if you turn them sideways.

I use plastic shims also. Have a set of Harrel precision aluminum rings. They are great, but they do leave marks.

It would help if I would set it and forget it, but I tend to move a scope a 100 times till I get it right. That is what marks the scope.

Anybody ever tried glass bedding rings?

Only shims as well. I use one and on a very few occasions two pieces of painters tape on the inside bottom of the rear ring.

Maybe the right way is at the base. There’s a number of options on the market to go at it that way. BKL has a one piece mount for grooved receivers and there’s lots of options with standard screw on rails and bases.

I have a EGW 20 min base on a long range handgun, I think 10 min would have worked just as well. The one piece base is heavier than 2 pieces, but I don't know why you couldn't cut out the center as long as each end was kept properly oriented.

I always put shims under the scope base. Usually .010ths will do the job.

Al Foust