Problems with m1 Carbine (hope this is the correct place to post)

[mchatcommander]

I have an m1 carbine that I swear is just a lemon, I feel like I have put a lot of work into it and it just doesn't want to function without problems.

My current problems:
This one has always been a problem, see picture for hopefully more clarity. When I put a full magazine in the gun the magazine will lean down because of the weight which prevents the gun from feeding in another round. The round will hit the magazine well and jam. I can fire it if I hold the magazine up, but I don't feel like that is what is intended.

New problem is I am getting random misfires where the firing pin will hit the primer but not hard enough to fire the round.


Things I have done
replaced the springs, replaced the magazine catch with the additional nub for the longer magazines, bought new magazines(a g1 one and one of the Koreon ones)

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[matthanne1]

may want to give which carbine manufacturer you have, and who made the magazines (not all makers are equal)! It sounds like the mag retention and catch is not operating properly which could be wear, damage or improper assembly, and this could be also wear or damage to the mag as well. Not even talking about the firing pin issue yet, which is potentially another host of related issues (corrosion, damage, ammunition). Sounds like you just need to dispose of it altogether, I'd take care of it for you...lol! like I need another project....

[jimb16]

Without more info we are only guessing. If I assume good mags and a good mag catch, then the problem could be a bent/damaged trigger housing. If the mag well has somehow been stretched/elongated, that could be the source of the problem. But I'm going to call that improbable. I've only seen this once and that one had been hammered on and was slightly bent. The other possibility is that the mag springs are in backwards. This allows the rounds to dip when being pushed forward by the bolt. Try rotating the mag springs 180 degrees and see if that solves the issue.

[JackP]

I had a similar problem with my early QHMC. It turns out that the Type 2 mag catch/safety plunger spring assembly is longer and exerts more force against the mag catch and in turn pushes the magazine forward, raising the front and making feed easier. The longer assembly was originally intended to improve the operation of the flip safety but it also helps lift the front of a heavy magazine. The Type 2 should have an overall length of 1.00", /.10" longer than the Type 1 at .90". This is one of the "must change" parts for rebuilt carbines. When I changed mine from Type 1 to Type 2, it worked fine. It's worth checking it out.

[DaveHH]

Carbines are very ammunition sensitive. If you are using reloads, the cartridge must be exactly the correct OAL. If they are too long, the tip of the bullet will drag against the front wall of the magazine and not feed well. 30 rd magazines are always trouble, the are just too heavy and if the nibs are worn on the back, they will rattle all around in there.
As far as not firing, the recoil spring is usually the culprit and the carbine should be greased just like the big rifle. Before doing anything, I'd make sure I had good factory ammunition and new 15 rd magazines. Start and go from there. The last time I fired my NPM, it was giving me trouble and it turned out to be debris, dirt, carbon general guck under the extractor. I disassembled the bolt and cleaned it and problems disappeared.
Don't lose hope, these guns are very,very good firearms. The fact that they have been used for 76 years is good advertisement.

[jimb16]

DaveHH has a good point about failures to fire. Often dirt and grit built up under extractors will prevent the bolt from closing completely and it often goes unnoticed. The bolt then finishes closing when the hammer hits the pin, but the round doesn't go off. This results in a light primer hit or just a small mark on the primer. If this is what you are finding, tear down your bolt and give the extractor and spring a good cleaning. That should clear up that problem.

[browningautorifle]

If you are using a 30 rd magazine you should have the later style magazine catch. The magazine catch was re-designed to incorporate an arm to help support the added weight of the magazine.

He said he did...that...

Things I have done, replaced the magazine catch with the additional nub for the longer magazines

[Bruce McAskill]

You show a drawing of a 30 round magazine. Have you tried a USGI 15 round magazine?

[USGI]

Have you tried a USGI 15 round magazine?

His original post says he bought one, so probably has tried it. Although, I had a new KSG mag that stripped the lugs the first time I tried it. - Bob

[mchatcommander]

I have tried the 15 round magazine, and I believe it was not a problem at least with the new one, it seemed to be a problem with the old ones that came with it. (I only tried it once though)

These were the new mags I purchased:
KCI-MZ026 KCI M1 .30 Carbine 30-Round Magazine
KCI-MZ025 KCI M1 .30 Carbine 15-Round Magazine

I have only used purchased ammunition, thought I don't know the brands off the top of my head. I used two brands, I think I had misfires from both. 3 out of 45 rounds. All three rounds were able to fire when I reloaded them and shoot them again. I know that if you don't let the bolt slide back on its own when you rack it back it will not fire either. I am wondering if it is not getting enough blow back to throw itself forward all the way. Sorry don't know all the lingo.

Any more information you need? I can provide actual pictures of the gun as well. Or answer anymore specific questions.