M1 garand failure to feed

[nhyrum]

I would inspect the gas port hole to make sure it is free of obstruction, and to measure its diameter while I am at it. No fancy gauges are needed. A set of number drill bits will do.

Manually pull back the charging handle to determine the position at which the bolt can reliably pick up a fresh round and add margin of 1/8" to 1/4". Mark that position and put masking tape on it so that the charging would hit it when it travels beyond that point.

Fire a clip or two and check the tape after each shot. If the tape is broken and yet bolt over ride happens, it is probably not the gas system.

Other than the gas system, the issue can also be caused by hesitation of the round column going up in the clip. The round must be there on time for the bolt to pick up.

Gas system deficiencies, leakage, undersized gas port, low port pressure etc, can definitely be the cause.

-TL


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Yeah, I do not have to appropriate drill bit set to measure the gas port. But I haven't visually checked it.

I like the tape idea, I'll give that a go. I'll have to pick up more m2 ball. I might buy some regular -06 designed for garands too

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[tangolima]

Something like this will do.

Drill America - DWD60J-CO-SET 60 Piece m35 Cobalt Drill Bit Set (Wire Sizes: #1 - #60), DWDCO Series https://a.co/d/6VV6zNW

-TL

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[Generic]

I hate to ask such a basic questions, but are you sure it doesn’t have one of those aftermarket adjustable gas plugs?

 

[nhyrum]

I hate to ask such a basic questions, but are you sure it doesn’t have one of those aftermarket adjustable gas plugs?

Don't feel bad asking basic questions, I'm sure it's something simple I forgot.

No, it's not an aftermarket adjustable/bleeder style plug that let's you shoot modern ammo.

I've yet to get the rifle out, when I do I'll inspect the gas port in the barrel, and make sure the magazine assembly is together correctly

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[Unclenick]

Nhyrum,

Does the bolt lock back after the last round and empty clip eject? Since the gun worked fine before you tore it down and reassembled it, I assume it does that, and this demonstrates there is nothing wrong with the gas cylinder, its spring, or the operating rod.

Locking back after clip ejection proves the bolt is moving back far enough to pick up a fresh round. It sounds to me like you installed a part upside down, which spoils the gun's ability to accelerate the magazine follower up fast enough to get a round in place for pickup before the bolt is already over the top of the magazine and heading back into battery. I know I did this once when I was new to the gun, but it was over forty years ago, and I've forgotten exactly how I did it. It may have been the little piece pinned into the operating rod catch assembly that I flipped over.

Yep. That's it. Looking at the blueprint, that part is called the accelerator and it helps accelerate the follower upward.

 

[nhyrum]

Nhyrum,



Does the bolt lock back after the last round and empty clip eject? Since the gun worked fine before you tore it down and reassembled it, I assume it does that, and this demonstrates there is nothing wrong with the gas cylinder, its spring, or the operating rod.



Locking back after clip ejection proves the bolt is moving back far enough to pick up a fresh round. It sounds to me like you installed a part upside down, which spoils the gun's ability to accelerate the magazine follower up fast enough to get a round in place for pickup before the bolt is already over the top of the magazine and heading back into battery. I know I did this once when I was new to the gun, but it was over forty years ago, and I've forgotten exactly how I did it. It may have been the little piece pinned into the operating rod catch assembly that I flipped over.



Yep. That's it. Looking at the blueprint, that part is called the accelerator and it helps accelerate the follower upward.

No, the bolt doesn't even go back far enough to eject a clip.

I really do think that I've just assembled it wrong, I'll look at it the manuals and make sure I get everything in correctly

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[Unclenick]

Edit:

I knew this had come up before. Here's a thread where a backward follower was a problem. However, reading the last post, it looks like the operating rod catch (drawing below) was not correctly oriented to have the hook clear properly, so he had a couple of issues you can check.


Edit, Edit:

For those curious about the accelerator issue, here's the gummint drawing showing its correct orientation in the operating rod catch:

 

[nhyrum]

Sorry for taking forever, gun is a little buried.

I believe I have the accelerator in correctly.

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[jcj54]

Yes

The parts in the picture are assembled correctly.

 

[nhyrum]

The parts in the picture are assembled correctly.

Thanks. I'll check what @unclenick mentioned about making sure the op rod catch was clearing and set properly

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[musketjon]

Screw the gas cylinder lock back on all the way and then just back it off enough to time at the 6:00 position. By backing it off 2 whole turns, it is blocking some of the barrel gas port hole, hence the short-stroking.

Jon

 

[nhyrum]

Screw the gas cylinder lock back on all the way and then just back it off enough to time at the 6:00 position. By backing it off 2 whole turns, it is blocking some of the barrel gas port hole, hence the short-stroking.



Jon

I initially had the problem with it screwed all the way in. With it screwed all the way in, from photos I shared, it appeared it was too far back. I've tried it all the way in (which is really more like very lightly torqued after making contact - like 5 degrees of rotation), backed off a turn, or backing off till it lines up again but not torqued, and backed off an additional turn

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