Gunsmithing How to fix scope mount?

[hntbambi]

I have a Interarms Mk X action that was just rebarreled to .375 Ruger. I was using a 2 piece base and Burris Signature rings that I thought would fix the minor misalignment of the front and rear mounts. I got a 1 piece 20 MOA rail for this thing and I find they are way off. I have 1" piece of aluminum round stock in the rings and the rings are mounted to the base.

Also the holes are not aligning up. The mount works great on my other Mk X actions. The front holes align great or the back holes align great, not all four holes though. Here is the alignment with only the rear screws in:

Here is the alignment with just the front screws in:

I am thinking that bedding compound can get me some better alignment, but the rear holes need to be filled in, re-drilled, and tapped. What is the best way to fill the existing holes? I am not opposed to 8-40 threads as this thing packs a bit of a wallop. But I don't think it will clean up the existing holes. I am open to suggestions.

 

[hero's machine]

Re: How to fix scope mount?

There are only a couple ways I know to skin this cat....

Slevetite (super locktite) some screws in and hand finish, re drill, tig it up and redrill.....remachine your base to fit the action.

Bedding it in place would possibly work, but never allow me to trust it.

 

[Jkob]

Re: How to fix scope mount?

I can make you a new one using the existing holes and some blank stock picatinny rail material.

Email me if you are interested.

[email protected]

 

[hntbambi]

Re: How to fix scope mount?

gundoktr,
Email sent. I looked closer at the action and I stretched a piece of monofilament from the rear mount hole to the muzzle and it looks like the holes are aligned properly. I guess the profile of the rear bridge is the culprit.

 

[tmcelrath]

Re: How to fix scope mount?

I have that 1 piece base i can run over to you to experiment with...

 

[Rprecision]

Re: How to fix scope mount?

That looks pretty rough,

I would do some measuring and fiqure out if its in your action or mount

 

[Kells81]

Re: How to fix scope mount?

What about going back to a 2 piece mount and using windage adjustable rings? the name is escaping me right now of who the hell makes them. Other than that you might be able to send it out and have a completely custom base made for it. It would essentially be Gundoktr's solution but would most likely be better as the person building it would have it in hand to take the measurements off it.

 

[Greg Langelius *]

Re: How to fix scope mount?

The windage adjustable bases are made by Leupold and were also made by others (Lyman, Redfield?).

I can and have used them in applications like yours that seem pretty hopeless. I have never trusted them. They appear flimsy, and I suspect their ability to retain a zero.

Despite these mistrusts, they have always worked for me. I have also always handled those firearms with extra care, to try and prevent upsetting my zero. That may be a necessity.

I would never attempt to move mounting holes in a receiver. Enlarge, yes, move, no. Change the removable part, not the foundation. I would elongate the holes in the base before I touched the receiver, and that's not even a marginally good solution. The best solution is a base that's been configured to match the receiver as it exists. Two-piece bases are not a kluge, and can be set up so they do not add torque to the scope tube.

Greg

 

[formal598]

Re: How to fix scope mount?

I can make you a new one using the existing holes and some blank stock picatinny rail material.