Shimming scope mounts

[Tyler Kemp]

I just bought a scope with a 30mm tube, and now need new rings. Midway has a Game Reaper 30mm rings and mount combo for $30, should work fine with my low recoil 6mm Ackley.

I would like to shim the mounts to achieve +20 or +25 moa, how much soda or beer can shims would I need under the rear base to achieve this?

Thanks!

[Varmint Hunter]

Originally Posted by Tyler Kemp

I just bought a scope with a 30mm tube, and now need new rings. Midway has a Game Reaper 30mm rings and mount combo for $30, should work fine with my low recoil 6mm Ackley.
I would like to shim the mounts to achieve +20 or +25 moa, how much soda or beer can shims would I need under the rear base to achieve this?
Thanks!

One piece base or two?

Personally I'd much rather use Burris Signature rings with the off-set inserts. Very easy to install and change if necessary. Won't bind or flex scope tube either.

Just a thought.

[Tyler Kemp]

It's one piece. I'll post an ad to trade my rings for 30mm ones.

[Buffalobob]

What is the spacing in "inches" from center of rear rings to center of front ring or from the holes in the action?

[Tyler Kemp]

5.025" if I'm doing my internet research right.

[Buffalobob]

You will need 0.00138 inches of shim thickness for each MOA .

So for 20 MOA of cant you will need 0.028 inches of shim.

Soda cans are thinner than beer cans. Cheap beer like Keystone and Bud has thinner cans than better tasting beer. Think about it. Kinda makes sense doesn't it.

You will have to cut and measure with your calipers to get the right number. To make the shim you can just use scissors. The aluminum will cut just fine. Cut out small "H" looking things that fit in between the screws and don't fall out while you are trying to tighten the screws down. If you put too much shim in you will need longer screws. Be careful here and don't tear out the thread in your action by trying to tighten in too short screws without good thread engagement. If the screws are too long they will bind the action. (Does it sound like I have been down this road myself?)

Sometimes it is good to glue everything in but you really need to be sure that is what you want before you do it.

If you are using a one piece base you will be OK. If you are using a two piece base you will need to lap the rings.

I have a set of Extra High Burris Signatures that fit a weaver base with inserts if that is what you need. They are good for 56 mm objective bells and no-taper barrels.

[Tyler Kemp]

They might be a bit high for my job but I'm sure they would work. How much are you wanting for them?