Had a rifle bedded and while it shoots nice little groups, the lowest I can get it is 5 inches above center. My understanding is putting a shim under the front mount should fix this. What is used for the shim? Using Athlon picatinny mounts. Any advice most appreciated, as I have never had to do this. Scope is a VX5 3X15.

Thanks

Black electric tape you can layer it

What kind of base?

beer can sliver

Did it shoot real high before bedding?

If it is shooting too high you need to shim the REAR scope mount. I use several layers of aluminum foil from the kitchen. Deer1

Brownell's sells scope shims drilled for the mount holes made out of steel shim stock blackened. you can make shims out of brass or steel shim stock if you have any or can find it.

Sorry, but that's wrong.

That's a great question.

Yup, just no AB products. Don’t want to gay it up.

Burris Z rings. Problem solved

Yes. Lift the front end of one scope.

Cut up a soda pop can .That works just as well for shims.

Bruin, You got me thinking. I think you are right. Sucks being old. Thanks, deer1

Buris Signature Zee rings with plastic inserts. They sell offset inserts which serve as shims, and never mar your scope.

https://www.amazon.com/Burris-Optics-Pos-Align-Inserts-Signature/dp/B000GU6NTG?th=1

Get another mount,sounds like you have a mount with some extra mils of elevation built in it.

No worries. I honestly had to think about it myself. I'm not exactly young anymore.

thanks guys. Good info. If a beer can, is one layer enough? If I use a diet soda can, will it help lower the weight? (sorry could not resist) And no, it did not shoot high before but there was not a lot of travel left in the dial.

I don’t think I’ve ever used more than one layer of aluminum can shim.

Easier ta shim the base, or buy a 20 moa base.

I don't know if these will work for you.
But they fit under Leopold dual dove tail bases.

They might fit per hole spacing under the picatinny rail.
Or you could slightly mod them if needed
They are .012 IIRC and a Leupold band aid fix per issues I had with with a VX 3I 2.5 -10×40 circa 2017.
Lupy fan boy from 1979 - 2017
Not anymore.....

Last Leupold anything in my house.

Your can have em if you want them.
PM me your mailing address if so.
I'm out whatever a stamp cost..
🥴🤣🥴
But gain a Leupold product free home.👍🏻👍🏻👍🏻

Would have never thought of it until this thread.

I can just pop em in a envelope and they will be on their way.

Shimming a scope in the ring changes the inside diameter and will distort the scope tube. Shim the base, lap the rings, save the scope. Or buy the Burris rings and use the inserts to fix the problem.

use the burris rings, shim just one base you are bending the scope when tightened.

with the burris the plastic inserts straighten up with the scope and keep you from bending it.

It almost sounds like you don't have a plane surface to start with. Prior to mounting your scope, did you check for burrs or distortion on the top of the receiver?

It's rare, but I've seen burrs on the screw holes that have prevented a perfect mount before. Though granted, it likely wouldn't have taken the travel out of the optic as you have described.

I have a Burris Signature ring that I use with one of my scope. You can buy inserts that are shimmed for these rings. It worked good on this gun.

25 years ago or more, living in the boonies, I filed off Weaver bases a bit on one side and shimmed the other side to compensate for screw holes in the receiver that were out of alignment. Moved the front one way and the back base the opposite. For the shims I used stainless steel injector razor blades with the sharp edge filed off. My intent was to get by until I could fix it right. It shot superb groups with the shimmed scope, so I never got around to fixing it. My son has the rifle now and it still has the same jury rigged bases, and it still shoots tight groups.