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

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)

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....

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.

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.

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.

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.

Quote:

---

Originally Posted by lgr1613

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...

Quote:

---

Originally Posted by mchatcommander

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

---

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

Quote:

---

Originally Posted by Bruce McAskill

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

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.

That sounds like a combination of possible problems. A dirty/partially plugged gas port and a dirty extractor spring. Either would contribute to that problem. Get a bolt tool and take down the bolt. Carefully remove the extractor/extractor plunger and extractor spring and clean them thoroughly as well as the hole the spring and plunger go into. Chances are, that will be enough to resolve that issue. Carbines can be sensitive to built up crude in the extractor system. And while you have the bolt apart, it would be a good idea to clean out the firing pin channel too. Crude can build up at the front of the hole and "cushion" the firing pin strike against the primer.

Quote:

---

Originally Posted by mchatcommander

Any more information you need?

---

What manufacturer made your carbine?

Quote:

---

Originally Posted by mchatcommander

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

---

Light primer strikes can be caused by a number of issues ie.., short firing pin, weak hammer spring, gummed up bolt, deformed firing pin, excessive headspace, action not fully closing (See jimb16 post #6 and #11), binding of the hammer within the trigger housing, broken firing pin.

Quote:

---

Originally Posted by W5USMC

binding of the hammer within the trigger housing

---

I had that one happen to me. It was caused by too much gap between the TH and the cut-out in the stock. The trigger pin would back out enough to allow the trigger or sear to cause the hammer to bind. Had to make a slightly longer trigger pin to get it working again. - Bob

Take a close look at the tip of the firing pin under magnification. Some are so worn and broken at the tip and yet look fine. There is usually a reason why a part is no longer in the carbine. The F.P. is one of the more troublesome parts in a carbine. Lots of trouble with heat treating.

I have some more pictures and I think the manufacturer.

I do have the firing pin tool and I can look at that, I have taken it apart before.

So in the manufacturer location below the rear site it says.
It is a National Ordinance.

OP
some background material for you

Commercial Carbines
M1CarbinesInc.com

National ord
National Ordnance

That may just explain all of the problems as its a commercially made carbine and not USGI. They were the New Inland or Auto Ordnance of its day. Some good but more with problems.

OK thanks for the advice, so I took a look at the gas piston, and noted that the bolt that holds the piston in was super loose which I understands a problem because all the videos I watches said it would require a vice hold it while you unscrewed it with the special tool(which dangit I can't stand how many "special tools" the carbine needs). So this was a surprise to be able to unscrew it with my fingers I have cleaned it out, i think/hope but I think I am going to need to buy a new bolt at minimum... and the stupid tool. I also took the bolt apart replaced the springs and cleaned it. Hopefully this will address the misfires.

Part of me thinks I should sell the gun and move on, but I have spent well over 200 dollars (sight tool, bolt tool, new rear sight, springs, magazine catch, magazine spring, couple new mags) I feel like I would lose 200+ dollars on this gun selling it.

As for the magazine issue I can think of two things buy an new trigger housing which might address the issue(but sink more money into the thing. or try to affix a piece of steel to the magazine catch to give it a bit more length so it can push against the magazine. Thoughts?

I will also see about head space. I don't know much about that.

I have read mixed reviewed of the National Ordinance, from their a decent gun to their going to blow up and kill you. Not sure what to think about it.

You don't need a tool for the castle nut that holds the piston in the gas cylinder. Use a good set of pliers to just tighten it down a bit. NOT supper hard as you can crack the cylinder. Put it back together and take it to the range for a trail. If you do get rid of it you can always list the tools here for sale. Good luck.

Quote:

---

Originally Posted by Bruce McAskill

ou don't need a tool for the castle nut that holds the piston i

---

Years ago I built one by grinding a 1/4" drive socket to make a tool. Works well, and quite cheap.

Quote:

---

Originally Posted by mchatcommander

I have read mixed reviewed of the National Ordinance, from their a decent gun to their going to blow up and kill you. Not sure what to think about it.

---

Then take it out and form your own opinion.

Quote:

---

Originally Posted by mchatcommander

I feel like I would lose 200+ dollars on this gun selling it.

---

You won't be the first guy here to get in over your head and take it in the butt after selling...