Discouraged about M1 carbine magazines

[Jefe]

A friend gave me a mixture of about 50 NOS and well used GI and commercial M1 carbine mags- mostly 15s w/ some 30's.
Frustrated that, except for NOS GI, most commercial and used GI are problems- FTFeed, FTEject etc.
On some of the problem well used GI, I've changed the springs w/ NOS GI springs and still problems.
Cked the orientation of the springs, still problems.

It get expensive to feed mags to ck them.

Venting- "GI" M16, G3, M14, FAL mags all seem to generally function well. No comparison w/ the "flipping a coin" to see if a M1 carbine mag works.

Was it always this way w/ M1 carbine mags?

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[floydthecat]

Was it always this way w/ M1 carbine mags?

I certainly can't speak for others, but I have three carbines. I have 5's and 15's of war-era and post-war manufacture. I have no 30's, but the 5's and the 15's have NEVER given me a problem in any of the three guns.

[RazorBurn]

I have a couple of USGI M1 Carbine magazines that are great paperweights too. It happens.

[Bruce McAskill]

Having problems with that many magazines seems to indicate a problem with the carbine instead of the magazines. If you place a well used USGI magazine in the well does in move up and down? If you push up on the bottom of the magazine does it seem to feed better? If so then the magazine catch needs to be replaced. If it still gives problems with failing to eject then look at the extractor first. Be sure it is clean, free to move and not chipped or damaged. Then look to the ejector. Can you push against it and it moves freely in and out of the bolt? If not then you need to take it out and clean it and the spring. Replace the spring if it's broken or bent. You can also check the castle nut for the gas system to insure that it doesn't turn much and the piston is free to move. Last make sure your carbine is cleaned, lubed and greased where needed.

[floydthecat]

Troubles lead to frustration....we've all been there. I don't think one can draw a correlation between a defective mag causing FTE. Once the round is chambered and fired, it's pretty much up to the extractor and the ejector. Loss of gas pressure, or an overly aggressive operating spring will contribute to both issues and I'll throw-in crappy ammo as well. If the bolt does not reach it's full travel, it wont strip the next round and a fired round may not eject for the same reason. To add to what Bruce suggest, finding another carbine to try those magazines in would be most beneficial in diagnosing the problem, at least you can rule-out/rule-in magazines.

[USGI]

What the others said, plus check for wear on the "lugs" at the back of the magazines. If you have a caliper handy, compare the measurement between the NOS mags and the problem ones. Lugs that are worn down, give the same symptoms as a worn mag catch - Failure to Feed. Some of the original mags had lugs that were soft, and didn't last very long before they were toast. The minimum measurement from the top of the mag to the bottom of the lug is supposed to be something like 1.5". Factory spec is 1.523" +/- .002". Good luck getting them to work! - Bob

[browningautorifle]

I think too that the carbine may be at fault. Make sure the ammo is good, factory... If the 15 rd mags look good then they should work. I never had trouble with GI 15s.

[Jefe]

Gentlemen, thank you for the feedback.

The NOS GI 15's and 30's work 100%.

The recoil spring is GI and NOS/ correct 10.25" length and just replaced extractor and spring. The ejector seems good- works freely and not damaged. I just cleaned and re-staked the gas piston etc.

Its many of the GI mags that have most of the finish gone or some patina to them or the commercial ones that seem to be iffy even when I replace worn/ rusty/ "weird" springs w/ NOG GI.

The 50-60% of these 50 mags that don't work are the well worn GI or commercial ones.


Another poster talked about checking feed lips to see that they are aligned properly. I'll have to ck that, too.