Anybody had to shim a scope?

I’ve actually never had to do this before, but I was out on the range at the weekend and decided that my .22-250 was just a little too high at 100 as I’d like to be dead on at 200. So I went to bring it down a couple of clicks and, well, no clicks left. Uh-oh.

I haven’t had to do this before, but if I recall correctly, you can either use scope shim stock for about $10 a square inch from the fancy pants gun shop, or use a doubled thickness of aluminum can with the edges smoothed on a wet stone after cutting to size.

Anyone use either method? How thick of a shim does one need to add to gain 1 inch of adjustment back at 100?

If my brain is working correctly, I’m assuming I want to shim under the REAR ring. Correct?

Grouse

If your shooting a little high at 100 yards and want to shim it so you can impact correctly at that “100 yard distance” shim the front ring.

I’ve done the beer can thing a couple of times and was not happy with the long term results. I have a Browning A-Bolt that has mis-aligned mount holes and used these to correct it. Been very happy with how they worked out.

http://www.burrisoptics.com/signature-rings

Burris signature zee rings. Have adjustable inserts that let you adjust up to 30 moab. I have been extremely happy with them. And they hold up on my 50bmg .

Jeff Heeg wrote:

If your shooting a little high at 100 yards and want to shim it so you can impact correctly at that “100 yard distance” shim the front ring.

Every time I think about this, my brain hurts and I come up with a different answer.

To state the issue clearly, I’m trying to bring the point of impact DOWN about .5 inches, but I am out of “down” adjustment on the scope.

So I should shim the front UP?

Randy Wieland wrote:

I’ve done the beer can thing a couple of times and was not happy with the long term results. I have a Browning A-Bolt that has mis-aligned mount holes and used these to correct it. Been very happy with how they worked out.

http://www.burrisoptics.com/signature-rings

Yes, I’ve seen the Burris mounts recommended before and that’s certainly the gold standard fix.

Randy do you think I should shim first just to confirm the problem and the fix? Could this issue be something completely different? I don’t want to spend a bunch of money and find out I’m barking up the wrong tree.

I’m really vexed by this issue, I’ve never had this happen before and my other Axis in .223 was zeroed in about 5 clicks after bore sighting.

This is a Savage Axis .22-250 with a Bushnell Elite 6×24 (the older Japanese made one, not the new one) with Weaver base and Weaver rings.

Grouse

If it comes down to having to change the angle of your scope so you can aim at a dot at 100 and impact it versus impacting high and sad to say your all out of travel to dial — then raise the front of your scope–muzzle end.

Jeff Heeg wrote:

If it comes down to having to change the angle of your scope so you can aim at a dot at 100 and impact it versus impacting high and sad to say your all out of travel to dial — then raise the front of your scope–muzzle end.

X2. If your out of travel, I think your stretching the capabilities of a mid to lower end scope. I ;don’t know what you have for a scope and this may be repetitive to what you already know – stating this for others that may have the same issue.
If your scope has 20MOA in elevation, then you have 10MOA from center to top end or center to Bottom. Some lower end scopes lack in quality when you have the travel maxed out and it is always ideal to have your crosshairs meet your point of impact with the least amount of movement. So given that you had to travel so much, I would most definitely utilize something that would alter the angle to get the axis of your barrel and the axis of your scope more parallel. Even if you do an aluminum shim “test” and then replace with appropriate rings later

Thanks for the replies. The scope in question is a Bushnell Elite 6×24, but it’s the old style/model Elite that was made in Japan with Japanese optics, not the current model. It’s a front-focus, 6x24x40.

It has 13 inches of adjustment (26 MOA or exactly .3 metres at 100).

The base and rings are a Weaver (real, not generic) base and Weaver Quad Lock rings. I have this exact setup on another rifle and have never had an issue, but anything can happen.

These older Elite scopes were well regarded and both new and used ones command prices above that of the current new model. I haven’t read of any systematic issues with these scopes, so that leads me to think my suspects are:

1. Bad mounting setup somehow. No idea how, but something could be hung up, torqued, etc out of alignment. I will take apart and remount as the first stop and check everything for trueness and alignment.

2. Receiver out of plane with barrel. Strange, but does happen.

I’m going to first pull everything down, switch the front/back rings, remount, bore sight and try again.

If that doesn’t fix it, I’m going to shim just to confirm that the receiver is the issue.

Very strange this issue, but it does happen. In over a dozen rifles and scoped handguns I’ve mounted scopes on for myself or others, I’ve never had this happen before so clearly my luck has run out.

Grouse