What's wrong with my M1 Carbine??

[rod5591]

My M1 Carbine is giving me problems. When I first got it, it seemed to work well. I really loved firing it, and the way it worked. It has very little recoil and it was a lot of fun to fire off 30 rounds quickly.... But then, after I shot off a few hundred rounds, when I fired, the bolt would not blow all the way back and would not eject the spent shell. I had to manually work the bolt and eject the spent shell.

In disassembling the rifle to clean it and look at the gas cylinder, I see that the gas cylinder seems to be threaded off-center, at a slight angle. See Pic. Could this be the cause of the trouble, and is this correctable? How would I go about fixing this?

Worse yet--it embarrasses me to say this--I took the trigger pin out and now I cant get it back in. :banghead: The parts inside the trigger housing--the trigger and trigger spring, I think, no longer line up right to allow the trigger pin to be re-inserted.

What should I do, do you think?

By the way, my receiver is stamped "National Postal Meter" but the barrel of the M1 is stamped "Underwood". Does this mean the M1 carbine is not an authentic WW2 model but a post-war model made from parts?

Thanks for any help.

 

[Fleet]

1. Your gun is probably just dirty and dry (no lube).
2. The NPM receiver and Underwood barrel probably means an arsenal overhaul.
3. What pic? I think you forgot something. As the part you refer to, if it worked before you took it apart, it'll work when you get it back together assuming it's clean and lubed.

 

[dprice3844444]

get an m1 carbine piston wrench from sarco or numrich arms.gas piston maybe fouled.are you properly lubing it?

 

[Jim K]

NPM used some Underwood barrels, so it is likely that the carbine is original in that respect.

Jim

 

[rcmodel]

A Underwood barrel on a NPR is perfectly normal.

NPM had no barrel manufacturing ability.
They used barrels obtained from some other source that did make them.

The only M-1 Carbine barrels made during WWII where made by:
Inland - Division of General Motors
Winchester Repeating Arms
Underwood -Elliott-Fisher
Rock-Ola Manufacturing Company
Saginaw of Saginaw, MI
IBM - International Business Machines

rc

 

[rod5591]

I could have sworn I posted the pics. Here they are.....

 

[dfariswheel]

That's bad.

Either the gas cylinder wasn't threaded straight (defective barrel), or the gas piston nut is cross threaded.

To disassemble you need a gas piston nut wrench and to know how to do it.
Here a site with GI Ordnance manuals on the M1 Carbine. These show how to work with the gas system.
NOTE the info near the top of the page on what password and user name to use to get entry:

http://www.biggerhammer.net/manuals/

The manuals also show how to fully strip the trigger unit and reassemble it.

If the barrel is defective it should still work.
If the nut is cross threaded that's going to be a problem because I don't think it can be corrected.
If it is cross threaded you'd need a GI gas cylinder tap to try to straighten the threads.
If the gas cylinder threads are good and it's the nut that's damaged, just buy a new USGI nut.

 

[bigfatdave]

gas piston nut is cross threaded

Looks like it.

rod, with the right tool, that nut comes off easily, the tool isn't expensive but can be hard to find (I looked for months to find one, after I broke down and ordered from Fulton Armory they're at every gun show, go figure!) ... it is signifigantly easier and less damaging to use the special wrench than it would be to drive the nut off with a hammer and punch or make your own tool out of an old socket - I've done it both ways, get the wrench.

If you're lucky, the cross-threading has only damaged a few threads, and you can clean it up and put it in right, if they're all borked you'll need a new nut at minimum.

This is another thing that can be fixed by someone with patience and a bit of know-how ... probably the gas system is fouled in addition to being misaligned, and both conditions together are the source of your malfunctions.

 

[M1C]

If you're interested in getting rid of that Carbine I'd like to hear a price.

 

[rod5591]

Thanks for the offer, M1C. I'm just going to figure out how to repair/restore my M1 Carbine. Even though I've only had it for a while, I really love that gun.

I am attaching another pic. Notice that the handguard is not wood, it's metal. Does that mean this is not a WWII carbine? Also, the stock has "FAT" on it, someone told me that means it was a Italian stock -Fabrique Arms Terni ?

 

[dfariswheel]

The vented steel upper hand guard was a common commercial addition for USGI carbines.
People seemed to think they looked cooler than the GI wood and often replaced them with these steel guards.
Remove it and buy a genuine USGI walnut handguard.

Have no fear, National Postal Meter made ONLY USGI M1 Carbines, never commercial carbines.

 

[rod5591]

Remove it and buy a genuine USGI walnut handguard.

sounds like a good idea

 

[rod5591]

Ok I had some work done on the M1 carbine, and I had a new gas cylinder installed. It mostly works OK-- however sometimes the cartridge doesn't eject--it stays there in the rifle. See the pic. I have to pry it out with a tool.

What is the cause of this?

 

[Rottweiler]

Is that an aluminum case stuck in there or does it just not photograph well? If it is, that maybe the problem. If it is brass, I'm thinking weak extractor spring or possibly a worn extractor.

 

[eastbank]

rod5591,pm me your address and i,ll send you a extractor for postage. eastbank.

 

[dprice3844444]

try a different ammo mfg,might be underpowered/lighter loads
http://www.calguns.net/calgunforum/showthread.php?t=211196
http://www.ak47.net/archive/topic.html?b=6&f=6&t=234250
http://kmike.com/M1/TM9-1276_1947.pdf manual

use brass ammo only also,because of age,an extractor spring/recoil spring replacement might help. read above

 

[velocette]

Rod,
You can go here: http://forums.thecmp.org/forumdisplay.php?f=6
For a forum dedicated to the M1 carbine. A lot of wisdom and experience there.

 

[Jim K]

Yes, FAT means Fabbrica d'Armi Terni, the Italian government arsenal. I don't think any Terni stocks were sold here so it is likely that carbine was sent to/left in Italy as military assistance, then returned and sold, possibly through DCM or CMP.

The nut is definitely cross threaded and you should not fire that carbine until the problem is corrected. If only a few threads are bad, you can probably correct the problem easily. Note that the nut has to be in to the point where the bottom of the castle nut cutouts is even with the edge of the cylinder. Then a center punch or a dab of blue loctite can be used to keep the nut from turning.

Jim

 

[Lee Roder]

The only M-1 Carbine barrels made during WWII where made by:
Inland - Division of General Motors
Winchester Repeating Arms
Underwood -Elliott-Fisher
Rock-Ola Manufacturing Company
Saginaw of Saginaw, MI
IBM - International Business Machines

rc

Mostly correct. Both Buffalo Arms and Marlin, while neither manufactured any M1 carbines, produced nearly a quarter million barrels for other manufacturers during the war. The Brown-Lipe-Chapin Division of General Motors also produced barrels for Inland to supplement Inland's own manufacture of same.

 

[rod5591]

Thank you all for the replies. I shot another 50 rounds through my M1 Carbine, and kept records of the results. The ammo was factory ammo, 20 rounds of Remington 110 gr UMC and 30 rounds of Sellier & Bellot 110 gr FMJ. All brass casings.

6 of the 20 Remington rounds (30%) did not eject properly. 7 of the 30 Sellier & Bellot round (23%) did not properly eject. Combined failure rate was 24% .

Attached are pics of 4 of the rounds that did not eject properly. Also attached are 2 pics of the mags I used.

Any ideas as to what is wrong? What should I do to make the rifle fire and eject reliably?

 

[rod5591]

Here are the last 2 pictures.

 

[rcmodel]

Well it appears it opens far enough to extract and eject, but isn't ejecting.
So it's not likely a gas system or chamber problem.

Is the ejecter plunger & spring free to move in the bolt face??
My first guess is that it is stuck in the bolt from dirt or rust, or the spring has collapsed.

rc

 

[rod5591]

Is the ejecter plunger & spring free to move in the bolt face??
My first guess is that it is stuck in the bolt from dirt or rust, or the spring has collapsed.


It looks OK to me, I don't see any rust. I pressed the ejector and it did not want to move at all. So maybe I need to open the bolt assembly and check the ejector spring?

 

[rcmodel]

See if it moves.
Hook an empty case under the extractor hook, and pivot it straight with the bolt to compress the ejector plunger.

I can't tell much from the photo, but maybe a drop of oil here and there might also be good.

If it moves, oil it.

rc

 

[Carl N. Brown]

If you replace the extractor on an M1 carbine, it pays to replace the extractor spring. My 1943 IBM M1 carbine had an extracor spring that crystallised over the years and had snapped in two places; it fell out in three pieces when I removed the plunger.

The plunger on the extractor is a tiny little thing. It has a flat on the tip that must engage a corresponding flat on the extractor. Once aligned they stay aligned.