where do you obtain it?

I also posted this query in the optics section here.

I have had the same soft brass sheet of shimming material for so long that now when I need to replace it I am wondering if this is still the material of choice for many, or if there is another material that is better liked?

Then, where do you go to obtain this scope ring or scope base shimming material?

I have a 10/22 "light varmint" model whose reciever holes were put in just enough 'off' that It cannot be zero'ed, but it shoots such itty bitty groups I don't want to send it off and have it re done or played with by the factory. Far from the first rifle I have encountered like this.

Thanks in advance.

cup a pop or beer can.

McMaster carr

For stainless actions I use stainless stock
for all others I use brass you can order it in any thickness you like down to .0005"

Do your self a favor and either buy or make a shim stock punch for the holes.
Cut the shim as close to full length and width as possible. Do not cut strips and try to shove them in. you will have unequal contact and the base will get screwed down cockeyed

It's a good thing that this is a virtual campfire. If it was real, anyone with an milligram of character would ostracize you for your history of bad acts and total lack of contrition.

Have you ever read the fable of the scorpion and the frog?

Back to our regularly scheduled program. For blued steel I like steel shim stock. Cut to exact size of the base you can cold blue and edges all but disappear. No brass or aluminum lines or gaps.

Brownell's has it and some precut shims. I've seen steel shim stock in some hardware stores (rarely) and auto parts shops. "Fun" stuff to work with being so thin. I epoxy to heavier steel sheet scrap, work it, then heat to pop the shim off.

I don't shim inside the rings. Even for elevation I prefer to make the base itself fit right.

I simply bed the gap with epoxy, the perfect thickness is achieved every time. Yes, it sticks to the bases but the POS action obviously isn't even front to back if you need to shim so it is the lesser of evils. No doubt about a minimal stress mounting.

LOADS of real and useful help here, gentlemen! Much thanks and Happy Thanksgiving.

MARK

Unbelievable.

Would do the same with J-B Weld and use a release agent on
the receiver. If it doesn't come out right, the base can be
removed, sanded, and start over. Actually, I use one-piece
bases on everything and bed all of them in this manner. Very
few actions/receivers are completely true from one end to the
other.