Duplicated barrel larger than factory

[370bc]

i have a kimber montana that has a duplicated douglas barrel on it that is not free floated because of being slightly larger diameter. The forearm area of the stock next to the barrel is almost nonexistent. Using a barrel channel tool seems out of the question. The stock is made of Kevlar and carbon fiber.
I would take it back to the gunsmith, but since then we have had a falling out. It had at first, shot good groups at first, but Now it is acting a little funky. It/me Shoots good one day, then not so much the next, with viraity of loads. The barrel is not floated whatsoever. It looks like if it could be just shimmed up a little bit, but that might solve my problems. What do you suggest? Thanks in advance.

 

[Fast14riot]

Slightly taller front pillar/bedding?

 

[370bc]

Sounds good to me!

 

[RWO]

The easy fix is to shim the action up to give about .020" clearance in the barrel channel ( 4 thicknesses of copy paper). if that is not acceptable, I would have the barrel turned. There is no practical way to open up the barrel channel except by grinding or milling. That would involve cutting the channel oversize and then epoxy bedding the action/barrel with a tape wrap to give enough clearance. Then the new channel surface would require painting to match the existing stock finish.

RWO

 

[370bc]

Should I leave the paper backside on?

 

[370bc]

I took the paper off and I used 10 shims to get it fully floated. Did the trick! Thx a mill!

 

[fyrewall]

I would scrape out the barrel channel if those shims make for a funny receiver fit especially around the tang area. Be careful not to stress the receiver by application of large amounts of receiver screw tension applied to some shimmed pillar bedding system.

I use a GUNLINE barrel channel scraper on all types of stocks, wood and reinforced plastic (kelvar, carbon fiber or whatever) this type of stock is not hard enough to resist the 1/2 inch diameter hardened steel washers separated by rubber grommets on my GUNLINE barrel scraper tool (no grinding, this is not concrete). As the inside of the barrel channel is not visible what difference does it make if the inside finish is removed, if ascetically annoying get some matching auto touch up paint to cover up the scraped up areas.

 

[wholman]

can you not just sand out the berral chanel to make it fit.

 

[370bc]

can you not just sand out the berral chanel to make it fit.

There is not a lot of base material to begin with actually. it's branded as a mountain rifle, so everything is skeletonize to a bare minimum. I might have to tho. I shimmed it up, and it seems about 1/16 to 1/8 of an inch. Just guessing tho. The copper shims really seems to compress a lot after tightening action bolts.

 

[NorCalMikie]

If you still have daylight between the barrel and the forearm, who cares if the shims compress? If it's too much for your liking, add another shim.
You would be better off if you could get the forearm opened up a little. Sandpaper wrapped around a wooden dowel will also get the job done.

 

[AckleymanII]

Sand paper on a Deep Well Socket if you do not have a wooden dowel of the correct size will work well.

Re-bed the rifle, best option.

 

[tmwinds]

Sand paper on a Deep Well Socket if you do not have a wooden dowel of the correct size will work well.

Re-bed the rifle, best option.

This ^^. Find the correct diameter socket for the barrel channel and use sticky back sandpaper. 80 grit works well on wood stocks.

 

[jdh47]

If you have it shimmed and it is shooting well I would leave it alone. You're next barrel if done to specs better will fit. I think Krieger and I'm sure others will match a profile at a little extra cost. Something to think about for the next barrel.