M-1 Carbine barrel assembly

[loose noose]

Where would one get a barrel assembly for a Universal copy of a M-1 Carbine? I've checked Numerich however they don't have any, even for the US Military version. I noticed the cup that is attached to the original barrel assembly has a small crack, as the piston and rod fell out causing the arm to be inoperable. I'm wondering if I were to silver solder that hairline crack if it would hold up to any type of shooting? Note the piston and rod still screw back into that cup, however I just don't feel it would allow too many shots to be fired before working itself loose again.

Come on RC what do ya think?

 

[loose noose]

Still waiting on RC to comment, or anyone else that has a suggestion, sure would be appreciated. Note: the carbine is a Alpine, not a universal, and the cup referred to is the gas piston housing welded on to the barrel.

 

[carbine85]

Are you referring to the gas block and piston? A picture might help.
If it's the gas block that's cracked I would think proper welding is required instead of brazing.

 

[loose noose]

No it is the gas block housing. Actually where the piston and block sit. The threading inside the housing is still intact. The camera I've got won't depict the crack as, like I said earlier it is a hairline; but the piston and the block were working it's way out after several rounds were fired.

 

[rcmodel]

Find a REAL GOOD TIG welder in your area and have him take a crack at it.
(No pun intended)

I don't think silver solder will stand up to the piston slam-bang + pressure involved.

And the silver solder in the crack would make future TIG welding attemps very difficult without ruining the threads.

I think the gas piston nut is threaded 1/2-32 NS-3.
And you will probably need a tap that size to clean up the treads no matter what you weld it with.

http://www.mscdirect.com/product/04844338

rc

 

[carbine85]

I think the gas piston nut is threaded 1/2-32 NS?

I'll have to dig mine out and check. I know it's a bottom tap. If you have to clean the threads all the way down you will need the bottom tap.

 

[loose noose]

Thank you RC and Carbine, I do know a good tig welder as a matter of fact, and I do believe I've got the tap to re-thread the housing. Thanks again, I do appreciate it.

 

[rcmodel]

Consult with your welder before he flips the switch.

That is going to be a very delicate welding job to keep from burning through and destroying the threads inside.

I'd probably pack it with heat sink paste, unless he has a better idea?

At worst, put it together and let him weld the whole mess together.
You can clean the gas piston with carb cleaner or carbon solvent, if you shoot it enough to ever need cleaning again.

rc

 

[loose noose]

RC, talked to him this morning, and explained to him the situation, he can't give me any guarantees, but basically suggested what you said about putting it together etc. It just might be a permanent fix so to speak. At least until we can find a complete barrel assembly for it.

 

[BBBBill]

Thread a copper rod/plug to screw in. Leave it long to act as a heat sink. Should preserve the threads.
Might be worth the time to check whether you could use a GI barrel. Possible that minor adjustments would allow one of those to work.

 

[dprice3844444]

ebay,gunbroker,criterion barrels
http://criterionbarrels.com/barrels/m1-carbine

 

[carbine85]

If you can find a welder that actually knows and understands the properties of different metals and welding material you might be successful. It's been done.
FYI - The M1 Carbine isn't always a simple barrel replacement. You can't just thread on the replacement. Trying to find someone that can head space and ream the chamber ain't easy. Proper indexing doesn't always mean proper head space.

 

[BBBBill]

The Criterion barrels linked by dprice3844444 are sold short chambered so that you can ream them to correct headspace.

 

[loose noose]

BBBB, and dprice, Those barrels start at $265.00, I don't think he wants to pay that much, especially after I headspace it and the cost of s&h. I'm going to try and have it welded and see how that works. I've had this guy weld other gun parts for me and after a little persuasion they seem to work pretty good. BTW Carbine he does understand the molecular differences in metals.

Anyway I'll find out tomorrow if it works or not, wish me luck. I'll let ya all know how it turned out.

 

[loose noose]

Had the piston "brazed" and went out and shot it yesterday. He did a great job on it. Fired over 50 rounds thru it without any problems. The customer was very pleased also. Appears to be a permanent fix however cause I doubt seriously if you'll be able to unscrew the gas block from the housing, Should be good for at least a couple thousand rounds though. Again I want to thank all you folks for your suggestions. Saved the guy quite a bit of money and I'm sure he is appreciative also.