How to shim a scope base for more elevation

[@aussiesteveakastevecallagh2280]

I have used this process shimming in the past and it works great, I hod an issue with the lack of windage adjustment so I purchased a set of Burris XLT rings not cheap $200 in Australia there very time consuming to set up but work very nicely heaps of adjustment in elevation and windage , thanks for the video Mate and I hope the BS your going through with KZbin works out in your favour KZbin needs people like you and your awesome content Steve .

[@johnswoodgadgets9819]

I do this a lot because I prefer rifle scopes on my crossbows. I like the one set of graticules on the rifle scopes, and rely on click counts for changes in range. Once you get used to doing it, counting clicks becomes second nature. I have had to do it on crossbow scopes too, if the arrow speed is less than 300 fps. I like heavier arrows even if they are slower. They still go to the point of aim, and carry more momentum. You have a lot more drop with even the fastest arrow than you do with the slowest bullet. I like to keep my elevation adjustments mid-range. I just use shim stock from industrial supply houses. You get a lifetime supply for just a few bucks. Think I last bought it fifteen years ago.

[@inrangerimfire20two]

Cool idea! Thanks for sharing

[@davecollins6113]

Had a day when I had to put one in to shoot into a head wind @ 200yds, next day I was alout 7-8ft over the target, I was a bit shocked where it hit. I hadn't reset it, just tried it out, was surprised at how much difference I saw. Was just a pc of brass shimstock I had in my box, probably .020 or something like that. Mine was a flattop dovetail rail built on to the barrel, just trimmed a small pc to go between the ring base and the dovetail rail. That was with a 32-40win and 209gr bullets @ 1400fps. 6.5-20 leupold same as yours, front AO.

[@inrangerimfire20two]

Thanks for sharing. Yep, the shimming at the base works out to be quite dramatic down range.

[@cindymuss]

Had a problem with running out of up elevation so after some research, decided to try shimming. Didn't know if I was going to have any good results but I tried this anyway. Took some silver A/c tape and folded it once and applied to rear ring. Thickness measured .0135. Problem solved and now I am about in the middle of adjustments from highest to lowest.

[@inrangerimfire20two]

Hey there, yup shimming the inside of the ring will absolutely work, but just be careful when you tighten the ring caps as it is very easy to kink the tube now that the front and rear are different. I would suggest rings with 4 clamping screws so you can tighten them differently front to back to account for the angle. Thanks for the comment

[@tomalophicon]

​@inrangerimfire20two or you could shim the opposite half of the opposing ring.

[@bluntinstrument6070]

I think you are going to have to put a lapping tool through your rings to lap them and at least take the sharp edge off that has been created by the shimming . Well, I certainly would.

[@profesonalantagonist]

And now your rings are misaligned by 0.040”. No different than popping the shims between the ring and scope tube. Effectively the same, but one is bad or incorrect, and the other is ok.

[@johnswoodgadgets9819]

Shimming the base instead of one of the rings keeps the rings from biting into the scope tube. I suppose you could get some swayback in the mount, but I never had that problem. You can also get some strange binds that can translate into a different feel in the click detents if you shim the rings. Not the end of the world, but there is a better way. I tried shimming the rear ring a few years back, and abandoned the idea. Of course, as a crossbow shooter I probably use thicker shims than the rifle guys have to.

[@mrnice752]

@@johnswoodgadgets9819 No it doesn't. If the rings are still parallel and now offset you have exactly the same problem as when you shim inside the ring, the angled scope tube will still only contact the edges of the rings. This method allows you to lap the rings to the correct angle, but that's a lot of work to avoid buying angled mounts.

[@kevinforrester4937]

How long can you leave it like that without hurting the scope. I used four pieces of plastic jug on front mount.

[@inrangerimfire20two]

That depends on a few things, but 4 pieces sounds like quite a bit. It all depends how tight you are with your rings and the recoil. Mine was on a .22, so I didn’t have to tighten very much

[@kevinforrester4937]

@@inrangerimfire20two I tightened to 21 inches pounds and I have the scope on a .22 calibur magnum air rifle.

[@inrangerimfire20two]

@@kevinforrester4937 are they 4 bolt scope caps?

[@kevinforrester4937]

@@inrangerimfire20two yes they are four bolt creative xp mounts

[@inrangerimfire20two]

@@kevinforrester4937 perfect. If it was me I would apply torque based at the angle to each cap.

[@rshettle123]

Do it the right way and get a one or two piece adjustable mount.

[@anthonyvirgadamo898]

My scope is causing me just the opposite I need to raise the front of scope is this normal rem 742 semi 30:06 wearier mounts leopold 3x9

[@inrangerimfire20two]

Well, not normal per se. I would double check everything to make sure all is well with your mounts etc. in my case there was nothing actually wrong. I was using a Center fire intended scope on a rimfire and as a result i ran out of elevation. You may have an issue in any number of things, but if all is well, you should have no trouble zeroing at 100y

[@michaelhennegan9637]

Talk, talk, talk, and not say anything.

[@Whitchhunter666]

Beer can,

[@inrangerimfire20two]

Yep, beer can works, but I wanted to do it right and I explained why in the video. The aluminum shows up as “white” from the side and is quite visible. I wanted to have it steel and blue it so it virtually disappeared. Thanks for your comment.