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  #1  
Old 05-14-2012, 01:42 PM
OKC_Jim OKC_Jim is offline
 
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Location: OKC, Oklahoma
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Default M1 Carbine failure to feed problem

Hey Guys,

I could use a little help with a problem I am having with an M1 carbine. Occasionally it will fail to feed correctly. Sometimes the bolt goes completely over the next round in the magazine. Other times the round has started to feed but the bolt is smashing into the middle of the round. I would estimate this happens about every 1 out of 15 rounds. My carbine is well lubricated. It has this issue with two different USGI magazines. I have also tried two different brands of ammo and swapping operating slide springs. So, two different magazines, two different ammos, two different springs, and always well lubed, and nothing has helped.

Suggestions?

Thanks,

Jim
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  #2  
Old 05-14-2012, 01:48 PM
Quercus Quercus is offline
 
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Hi Jim,

Past experience suggests this should be a fairly cheap fix.

My first guess is that the magazine springs need replaced. Is it a surplus USGI magazine or current manufacture?

If that does not fix it, a second guess would be the slide spring. You did not mention if the springs you're using are USGI or not; I'd swap in a new USGI spring, if you have not already done so.

To isolate the problem faster and more accurately, make sure to only change one variable at a time.
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  #3  
Old 05-14-2012, 01:57 PM
OKC_Jim OKC_Jim is offline
 
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Quercus,

Thanks for the suggestions.

I did try changing only one thing at a time.

My first change was just ammo.

My second change was magazines. Both of my magazines are USGI. One appears pretty close to being new. I was going to replace the spring on the first but at the time the place I ordered from didn't have springs. So, I ordered a second magazine.

The third thing I tried was swapping operating slide springs. My new spring is NOS USGI. I'm not sure about the old spring but they look alot alike.

Thanks again for the ideas, any other suggestions?

Jim
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  #4  
Old 05-14-2012, 02:06 PM
HB of CJ HB of CJ is offline
 
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Posts: 267
Default Sounds Like A Defective Mag Follower Or Mag Spring

Grab an empty U.S.G.I. mag and see if you can push down JUST the rear part of the follower soos it sticks in the wedged position. If you can, there most likely is your problem. The fix is to slightly bent to increase the distance between the front and rear bottom portions of the follower to tighten it up inside the mag body. Having just the rear part of the follower push down should not happen and the entire follower should slide down instead. (wordy?)

The second easy fix may not apply as I (in my old coot old age) am cunfusing M16 mags with M1 Carbine mags. Ignore that man behind the curtain. Take your Carbine mag apart and observe how the top of the mag spring rests against the follower. Try slightly bending the spring coil sosss the top of the spring rests on the REAR underside of the follower instead of in the middle or perhaps thru a hole in the middle.

This will increase the spring pressure against the rear of the follower and sometimes prevent bolt over base stoppages which is usually caused by the mag..specifically caused by the mag spring NOT forcing against the rear of the follower thus preventing bolt over base stoppages. Gawd I need my coffee!! HB of CJ (old coot) Hope this helps. Some G.I. mags don't work.
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  #5  
Old 05-14-2012, 02:18 PM
meplat meplat is offline
 
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Location: AZ
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If they are USGI, they probably are pretty well "used" (although not necessarily, you don't say).

Try a new magazine, Your USGI versions are old and might have been "squeezed" (or stomped on over the years), which would interfere with their spring travel and would result in inconsistent feeds as the spring rubs the inside, even with new mag springs which otherwise function well in normally shaped magazine, or the lugs worn.

If a "new" magazine doesn't help, look toward the magazine catch. If it (or the mag's lugs but ruled out with new mag) is worn, it will allow the magazine to slip lower during firing, which will result in failure of the bolt to catch the next round ...


HTH


Last edited by meplat; 05-14-2012 at 02:23 PM.
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  #6  
Old 05-14-2012, 02:34 PM
todd440 todd440 is offline
 
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I assume this is only on the last few rounds of the mag?
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  #7  
Old 05-14-2012, 02:34 PM
Quercus Quercus is offline
 
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Jim,

Piggybacking on Old Coot and meplat's responses, I'd be inclined to try the new magazine exclusively.
Simple question, are the two springs equal length?
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  #8  
Old 05-14-2012, 02:36 PM
OKC_Jim OKC_Jim is offline
 
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Quote:
Originally Posted by HB of CJ View Post
Grab an empty U.S.G.I. mag and see if you can push down JUST the rear...
Both of my magazines slide down almost level; you can't push the rear down.

Quote:
Originally Posted by meplat View Post
If they are USGI, they probably are pretty well "used" (although not necessarily, you don't say).
Both of mine are USGI but both look to be in pretty good condition. One looked about new until I started using it.

Quote:
Originally Posted by meplat View Post
Try a new magazine...
What is a good source of new magazines?

Quote:
Originally Posted by meplat View Post
If a "new" magazine doesn't help, look toward the magazine catch....
I'll try that.


Any other ideas I can try while I wait for parts to show up? Lol for that matter, suggestions for other parts I might need to order?

Jim
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  #9  
Old 05-14-2012, 02:37 PM
TSimonetti TSimonetti is online now
 
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Location: Western Pennsylvania
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Ruth's carbine book mentions checking the gas port for a failure to feed problem... Also it's probably a good idea to check and make sure the piston isn't gummed up, and that the nut is tight.

Last edited by TSimonetti; 05-14-2012 at 02:39 PM.
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  #10  
Old 05-14-2012, 02:39 PM
OKC_Jim OKC_Jim is offline
 
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Quote:
Originally Posted by Quercus View Post
Simple question, are the two springs equal length?
Not sure which springs we are talking about here, but the magazine springs are the same. While, the old operating slide spring is about 1/4" shorter than the new spring.

Quote:
Originally Posted by TSimonetti View Post
Ruth's carbine book mentions checking the gas port for a failure to feed problem... Also it's probably a good idea to check and make sure the piston isn't gummed up, and that the nut is tight.
The piston isn't gummed up, but I'm not sure about the port. How do I check it?

ETA: Just stripped the carbine. Looks like my gas cylinder piston is loose. It is still staked in place so I can't turn it, but I can wiggle it. I'm thinking this is probabaly my problem? How do I tighten it? Do I need the wrench, or is there another way?

Jim

Last edited by OKC_Jim; 05-14-2012 at 03:06 PM.
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