Scope shims ... front or rear?

[SBfan]

Ran out of elevation so I need to shim the scope. I read an article about this years ago but unfortunately don't recall which end to shim. Which end should I shim and what would be a good shim thickness to start with?

 

[ShtrRdy]

If you have a scope which has a zero stop, the zero stop adjustment may be preventing you from dialing far enough.

Otherwise I would consider getting a set of the Burris Signature zee rings which have inserts to offset scope angle.

Signature Rings™ | Burris Optics

www.burrisoptics.com

 

[madmixerman]

I would shim the rear base.

 

[Ackman]

Ran out of elevation so I need to shim the scope. I read an article about this years ago but unfortunately don't recall which end to shim. Which end should I shim and what would be a good shim thickness to start with?

DO NOT use shims. Rings are tubes. They need to be on the centerline. If not they’ll want to bend the scope. Shimming one or the other takes them out of alignment. Burris Signature rings use floating self centering inserts that eliminate misalignment. Go to the Burris website, it’s very well explained on there. Those rings also eliminate ring marks. Don’t shim!!!!!

 

[209jones]

I was out with my 32-40 one day practicing, in a headwind, got to where I ran out of elevation, 209gr bullet @ 1400, 200yds. Had a pc of brass shimstock in the box, tried it, worked well, 1980's version 6.5-20x50 Leupold. Next day, forgot shim was still in it, shot about 7-8ft high,was hitting the hill behind the target board. Doesn't take a lot to move it a bunch. I was able to shoot 300yds with that gun in a normal day w/o needing any shims in it.

 

[BoydAllen]

It seems to me like there are a couple of types of scope users in this thread, those who know how to properly install a scope, and those who either don't understand what is involved in doing the job properly or do and simply don't care. Putting shims in rings is not something that is done for a proper scope installation because it virtually guarantees that the scope will be put under bending stress when the ring caps are tightened. Bending stress on scope bad.

 

[209jones]

It seems to me like there are a couple of types of scope users in this thread, those who know how to properly install a scope, and those who either don't understand what is involved in doing the job properly or do and simply don't care. Putting shims in rings is not something that is done for a proper scope installation because it virtually guarantees that the scope will be put under bending stress when the ring caps are tightened. Bending stress on scope bad.

This was on a dovetail style rail, between the ring base and rail, maybe a .020 shim, would put some stress on the tube, but, a super slow mo of a gun firing, will show the tube flexing anyway. That was a one time deal as an experiment that day, scope worked fine for another 30 yrs.

 

[C.E.Smith043]

Ran out of elevation so I need to shim the scope. I read an article about this years ago but unfortunately don't recall which end to shim. Which end should I shim and what would be a good shim thickness to start with?

I've shimmed scope bases before. I start out with 1 shim then add more of needed. Personally I make mine out of pop cans. You can cut it with scissors.

Shim the front base if you need more bullet "down"

Shim rear if you need more bullet "up"

 

[Jeff Porter]

I've shimmed scope bases before. I start out with 1 shim then add more if needed. Personally I make mine out of pop cans. You can cut it with scissors.

Shim the front base if you need more bullet "down"

Shim rear if you need more bullet "up

If I remember correctly, 1 pop can piece is about .002"

I prefer the Burris rings but have shimmed with pop cans and if I need a bit more or am concerned about marking the scope I’ll use milk jug slices.

 

[JSH]

Sorry gents, the only reason I would shim, is if it is out square to begin with, and that would be addressed quickly. People spend a lot of time and money getting a good bedding job, trying to make it as perfect as humanly possible. I have not seen anyone dig through the recycle bin for “parts”.
I doubt I will ever loan a scope out again.

 

[Ackman]

It seems to me like there are a couple of types of scope users in this thread, those who know how to properly install a scope, and those who either don't understand what is involved in doing the job properly or do and simply don't care. Putting shims in rings is not something that is done for a proper scope installation because it virtually guarantees that the scope will be put under bending stress when the ring caps are tightened. Bending stress on scope bad.

Yes!!!!