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RG1911
03-12-2014, 03:35 PM
I've been doing some testing of longer and higher-quality bullets in an M1 carbine and have concluded that the slow rifling used by all carbine barrels needs to be faster: 1-in-12 or 1-in-14 would be appropriate. I was thinking about boring and lining my Criterion barrel.

Then I remembered that a few months ago I read an article about shot-out/damaged .30 caliber barrels being "fixed" by cutting them down to stubs and then grafting on a 1903 .30 barrel. I *think* this was done to Garand barrels, but may well have been done to M1 carbine barrels.

The advantages (as I see them) are that rather than boring and lining my good (and expensive) M1 Carbine Criterion barrel, I could use one of the de-milled short barrels I got from Fulton Armory. The barrel to be grafted on could be a good take-off. So the stub could be bored and the barrel to be grafted would just need to be turned-down enough to fit the length of the stub.

I have the reamer and gauges.

Has anyone heard of or done this? (One person told me that this is commonly done with the Swiss K31.)

(I realize that trying to get accuracy from an M1 carbine may be an exercise in futility, but I've been playing with this for several years, off and on, and this is the last possible solution I want to try.)

Thank you,
Richard

akajun
03-12-2014, 03:43 PM
Problem is that on the carbine barrel, if you stubbed it out, you would still need to do other machining to attach the gas piston/block, front sight, etc...
I think lining would be my first option, followed by machining a barrel from a blank.

RG1911
03-12-2014, 05:10 PM
I was planning on stubbing it a couple inches forward of the gas block. Then all that would be necessary would be to redrill the port. This is all going on a carbine I've built that will be scope-mounted, so there won't be a front sight to worry about.

The grafting operation also appeals to me because the .30 cal liners I've found have a 1-in-10 twist, which is faster than I want.

Richard

SOFMatchstaff
03-12-2014, 07:30 PM
I have grafted barrels for my Lewis gun, used the stub end with the hard to do stuff on it, and turned the replacement tube from New Vickers barrels. It worked Great, got the Headspace back to my specs and and made the brass last longer than the bolt guns.

The carbine shouldnt be to difficult, just be picky when you drill the deep hole as to alignment , the shape of the stub doesnt leave a great many places to hold the work in the lathe, the threads being the best, hopefully there is enough of the old barrel in front of the gas block to get a grip. Are you going for a straight .600 liner diameter or do a Ruger mini type profile?

RG1911
03-13-2014, 01:38 PM
There's at least 8 inches forward of the gas block on the stub.

I'd be going as close as possible to the standard diameter so it would be a drop-in fit to the stock. If I can't find a skinny take-off barrel, I'd see if I could deepen the barrel channel. The problem with doing that is the barrel band retaining spring shaft usually passes through the very bottom of the channel. (When correctly set up, the barrel actually has to be pulled down a bit and should not touch the bottom of the channel.) If all else fails, I'd have to have the barrel diameter turned down.

Richard