Home Forums Hunting & Shooting Hunting Optics Shim a scope?

I redid the stock of an old, odd, Savage bolt action 30-30 of a friend. I got it looking great and replaced the ancient scope that seemed to touch the barrel. With new scope and mounts it is hitting way too low. I have never shimmed a scope but plan to try this one. Any no-cost or very low cost advice? I assume I would shift the lower rear of the scope. Sound right and do I need to also shim the front upper??? Total novice on this.


As an aside this is an heirloom from is grandfather and there is no manual to be found even after calling Savage. They discontinued this rifle before 1940 if I recall. Thought I screwed the pooch after taking it apart and wondering where the hell this little spring and bearing came from.

To raise point of impact you raise the rear end of the scope.

Did you check the alignment of the rings with alignment bars or similar? If the centerline of the rear ring is lower than the centerline of the front, then you can shim the rear base to fix the misalignment and raise the rear end of the scope. If the rings are already in alignment then shimming will bind the scope.

Cheap and easy fix, beer or soda pop can cut a piece to fit your rear base, drill hole for mount screws and you have a .01 shim.

Buy the correct rings. Shims are a last resort! Just my 2 cents.

Burris makes some rings that have a plastic insert to solve this issue without inducing uneven torque to your scope tube, which is what you are likely to do if doing a homemade shim job.

Brownells sells them, Midway sells them made by Burris. Zee rings would definitely be better but that would not be within the OP’s criteria of little to no cost. He also asked specifically about shims so I gave him a no cost solution. Nothing more, nothing less.

Shims are a great way to muck up a scope. Use the Z Rings. Buy once, cry once .

Never

old fashioned way was cutting shims out of an aluminum can or some brass shims. they would work but not the greatest or the best at times they were hard on scope tubes.

100% agree with what's already been put on here the Burris Zee rings with the inserts are definitely the way to go when you need such a beast..

I took have used the Burris Zee rings. I was satisfied with it.

For keeping things less expensive, I'd just use epoxy to bed the bases. Use an alignment bar in the rings, so they stay perfectly aligned and then there will be no misalignment on the scope tube. If the op is good, he can mill down the front base, to drop it down a bit as well. I'd probably do that, before messing with shims and bedding. But I'd definitely bed the bases, as soon as I got the fit close, and the scope angle right. That's what I did with my Mauser that had some alignment issues. Some old rifles are worse than others.

However, before doing anything, I'd be perfectly sure I have the correct mounts for said rifle. Wondering if the OP checked the ring alignment with alignment bars, before he installed the scope as well. Generally if something is wonky, you'll see that right away with a set of those...

Thanks to all for taking the time to reply.

I finally got a look at it again this weekend after some of years. Lo and behold they are vertical split rings. There went my shim idea. I completely forgot that. All I could remember was having to crank the tar out of elevation adjustments to get it close to aligning with what I was seeing through the bore at 30 yards sometime back at my folks house. Both my parents have since passed and my buddy has never taken the rifle out after I returned it to him.

Long story short, I put it in the rest and it looked off but after re-securing it seemed pretty close at 50 yards so I had him shoot.

Wasn't sure where it hit so I walked over to check while he waited and it was dead center fricking bullseye. I S Y N as Dad would say. He was ecstatic. We moved it to near 100 yards and he was at just about an inch. Best group of his life. Keep in mind he isn't a shooter or reloader or anything.

We set up for hogs later but it was slow. Just past dark he nailed a big raccoon at about 90 yards. So I had his rifle functioning properly (when I originally took it - it wasn't cycling), had refinished his stock, set him up with good low priced scope, he loved having a recoil pad I put on, and was beyond excited to bloody an inherited rifle. Even at over 50 years old the first thing he did was call his Dad to tell him his old gun has new life.

I felt so rewarded. It was a great weekend.

Thanks again for your interest and input.

Nice!! Sounds like a win win..

You shouldn't have been putting shims in the rings anyway. Shims belong beneath the bases.

I use them on 99’s, had to buy the offset kit to correct windage issues on two rifles.

I shimmed the rings few times due to scope hitting the barrel and it worked great, forgot there were there until I took it apart when I sold the scope and they fell out. No big deal just do both rings.

and if I remember correctly a point .010 shim made about 10 in at 100 yards..

Mathman that was next option at that point. Thanks for chiming in - I will go that route if ever needed. Glad I never touched it.

I am concerned that the scope had to be so adjusted to get to this point but I am sure he won't ever take the caps of the dials. It works for what is needed and that is way better than the shape it was in when he first showed it to me.


ldholton- just curious- how thick is the metal on an 8 oz soda can?

I don't remember for sure I'm thinking it was around . 005
but I'll catch you in aluminum can and measure it when I get back to the shop later today..

I could be wrong on this keep researching because it's been a long time since I played with the shims..

.010 inch starting , finished product .004 sorry.