M1 garand failure to feed

[nhyrum]

I've been fighting this issue for some time now. I made a post in the past, but the rifle doesn't cycle completely for about the first half of a clip, it short strokes.

Here's the story.

Bought myself a birthday/graduation present, and a bandolier of m2. Fired 3 clips, and everything worked great. I disassembled the rifle to clean it(I wanted to make sure it would work before I messed with anything), and started reloading for it. I used imr 4895 and 175 smk's. For some reason I have a thing for heavy bullets, but was aware of their tendency to bend the oprod. I started at 43.0 and eventually worked up to 46.5. nothing would cycle completely. After trying my reloads, I went back to the ammo that worked, and it didn't function. In the mean time, I stored the rifle with the action open, which I prefer to do.

What I've done:
Bought a replacement oprod spring

Tried changing the position of the gas cylinder lock, from one to two turns backed off. Two turns seemed to work best.

Bought a box of surplus m2 - at best the last 4 rounds cycled

Greased and oiled the gun, numerous times. Not sopping, but I do tend to go light on lubrication, but I've been heavier handed here. Light up medium coats of grease.

The rifle passes the tilt test. Not overly easy, but it's not "bad" but this is my first garand, so I don't know how easy it should be.

I'm thinking that what might have happened is storing the rifle with the action open weakened the spring, and I ended up bending the oprod without getting anything to cycle, which is why the ammo that did work, didn't, and even with a new spring, ammo that should work, didn't. So, before I send the oprod and gas cylinder out to be checked out, is there anything else I could do or check? I haven't checked the gas port, but I don't have gauges/drill bits to check it with.

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[veprdude]

Where did you buy the rifle? CMP?

 

[nhyrum]

Where did you buy the rifle? CMP?

It was a CMP rifle, but I bought it from a private seller

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[44 AMP]

Find and get copies of the Army FM (field manual) which includes the user instructions and company level maint, and if possible find the TM (technical manual) which is the Direct support and General Support maint shop manual.

The FM will tell you what ammo and how to lube the gun and with what, the TM won't tell you that, but will give you parts specs, serviceability specs, tests and gauges used.

The M1 Garand went away just before my time in the service, but I was Small Arms Repairman trained on the M14. The M1 Garand TM will probably start with 9-1005 and then -XXX- 34, though I don't remember the number exactly

And, for the record, I don't believe it is heavy bullets that bend op rods. IT is powder charges that create pressure curves outside the Garand's intented operating range that bend op rods. Not just peak pressure, or gas port pressure but the entire pressure curve is a factor.

These loads are most common using the heavy bullets, but its the load, not the bullet that does the damage.

 

[nhyrum]

Find and get copies of the Army FM (field manual) which includes the user instructions and company level maint, and if possible find the TM (technical manual) which is the Direct support and General Support maint shop manual.



The FM will tell you what ammo and how to lube the gun and with what, the TM won't tell you that, but will give you parts specs, serviceability specs, tests and gauges used.



The M1 Garand went away just before my time in the service, but I was Small Arms Repairman trained on the M14. The M1 Garand TM will probably start with 9-1005 and then -XXX- 34, though I don't remember the number exactly



And, for the record, I don't believe it is heavy bullets that bend op rods. IT is powder charges that create pressure curves outside the Garand's intented operating range that bend op rods. Not just peak pressure, or gas port pressure but the entire pressure curve is a factor.



These loads are most common using the heavy bullets, but its the load, not the bullet that does the damage.

I do have a copy of the manuals, I have 3 different ones. Tm 9-1005-222-35(ds,dg and depot maintenance manager manual), tm 9-1005-222-12 (operator maintenance manual) and fm 23-5.

-35 has a troubleshooting section, that unless it's carbon in the gas cylinder or gas port, it's pretty much a bent op rod (it lists a few other things, like over sized gas cylinder or an out of round or undersized piston, but as the rifle functioned when I received it, I don't think those would have changed)

And yes, I guess I was over simplifying by saying it's the heavy bullet that bends the op rod, it is the pressure used to drive those bullets

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[tangolima]

Exactly what happens when it fails to feed? You mentioned short stroke. Does it fails to eject, to pick up a fresh round, or fail to chamber the fresh round? When you manually cycle the action, do you feel it is rubbing anything? Did you notice any friction points on the metal or wood when you disassemble the rifle? Any scratch marks on the ejected brass?

-TL

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[44 AMP]

Pardon the Captn Obvious question, but are you certain you got the rifle completely and correctly reassembled??

I ask because I once had an issue with an M1A (M14) cycling, where the problem turned out to be I was one thread short of having the gas cylinder plug all the way snugged up. Entirely my fault, and when correctly reassembled, the issue went away. The M1 Garand is slightly different, I know, but could have something similar happen, so, I ask...

OK, you have the right books, at this point you shouldn't need the gauges, until we can better isolate what should be checked, and if it does.

Short stroking isn't very specific, details of what it is doing, when, would help troubleshooting.

I would recommend not storing the gun with the action open. Modern springs are not supposed to be harmed by storing them compressed but "not supposed to be" and "will not be" are not exactly the same things. Also storing with the action open lets stuff get in there, where it shouldn't be, so I think its a poor practice.

 

[jcj54]

M1 short stroking

1) measure the diameter of the op rod piston with a micrometer, not a caliper.
Must be .5250 minimum
2) if the piston is not undersized, the probability is that the gas cylinder is worn oversize.

Only way to check properly is with a GI gas cylinder gauge. In 35 years of working on Garands, this is the most likely cause of short stroking when the op rod passes the tilt test and the rifle is properly lubricated.
As to a bent op rod, that is not likely, a bent rod usually won't pass the tilt test.
Also a weak op rod spring would not be short stroking as resistance to the gas pressure would be less.

The M1 was designed to work with caliber .30 M1 ball ammunition developed prior to the Garand being designed. M1 ball had a 175 grain boattail bullet with a muzzle velocity of 2700 fps and was designed for use in machine guns to create plunging fire on reverse slopes. It was supposed to be used in rifles and machine guns. This load wouldn't damage the op rod. 180 and heavier bullets have been known to cause op rod damage when loaded with powders that create too high of a gas port pressure

M2 ball was developed for the National Guard to duplicate the 150 grain WW1 cartridge because M1 ball was overshooting the safety zone of National Guard ranges.This became the standard ammunition issued for the Garand.

PM me if you want to discuss further

 

[Jeremy2171]

You may be at the point you need to send it to a garand specialist. If you can't get it sorted I'm in NC and would be glad to fix it for you.

 

[nhyrum]

Pardon the Captn Obvious question, but are you certain you got the rifle completely and correctly reassembled??



I ask because I once had an issue with an M1A (M14) cycling, where the problem turned out to be I was one thread short of having the gas cylinder plug all the way snugged up. Entirely my fault, and when correctly reassembled, the issue went away. The M1 Garand is slightly different, I know, but could have something similar happen, so, I ask...



OK, you have the right books, at this point you shouldn't need the gauges, until we can better isolate what should be checked, and if it does.



Short stroking isn't very specific, details of what it is doing, when, would help troubleshooting.



I would recommend not storing the gun with the action open. Modern springs are not supposed to be harmed by storing them compressed but "not supposed to be" and "will not be" are not exactly the same things. Also storing with the action open lets stuff get in there, where it shouldn't be, so I think its a poor practice.

No, I'm not certain I got the rifle back together. I followed about 5 separate YouTube videos, including a series by Brownells, so I'm PRETTY certain, but not certain.

I don't have the tools and gauges necessary to measure things like the gas cylinder or piston.

I have stopped storing things action open. I have chamber flags now.

It will eject, but not pick up a new round. The bolt closes completely, and doesn't hang up. But manually cycling the bolt after, it works just fine.

Could it be I have something in the magazine together wrong?

I think I'm going to try to send the oprod and gas cylinder out to be checked and repaired if necessary

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[nhyrum]

1) measure the diameter of the op rod piston with a micrometer, not a caliper.

Must be .5250 minimum

2) if the piston is not undersized, the probability is that the gas cylinder is worn oversize.



Only way to check properly is with a GI gas cylinder gauge. In 35 years of working on Garands, this is the most likely cause of short stroking when the op rod passes the tilt test and the rifle is properly lubricated.

As to a bent op rod, that is not likely, a bent rod usually won't pass the tilt test.

Also a weak op rod spring would not be short stroking as resistance to the gas pressure would be less.



The M1 was designed to work with caliber .30 M1 ball ammunition developed prior to the Garand being designed. M1 ball had a 175 grain boattail bullet with a muzzle velocity of 2700 fps and was designed for use in machine guns to create plunging fire on reverse slopes. It was supposed to be used in rifles and machine guns. This load wouldn't damage the op rod. 180 and heavier bullets have been known to cause op rod damage when loaded with powders that create too high of a gas port pressure



M2 ball was developed for the National Guard to duplicate the 150 grain WW1 cartridge because M1 ball was overshooting the safety zone of National Guard ranges.This became the standard ammunition issued for the Garand.



PM me if you want to discuss further

I don't believe there is any wear, eg, piston or gas cylinder sizes out of spec, as one clip functioned, the other didn't, with the real only difference being I took the gun apart in between (and some have loads shot too)

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[44 AMP]

Not an expert on Garands by a long shot, but I seem to remember reading something about there being a part in the feed system that could be installed upside down or backwards or something like that.

Right now, I'd say not to bother sending the op rod & gas cylinder to anyone to be checked. Find a Garand expert and take/send them the entire gun and have them check it over.

It worked before, you messed with it, it doesn't work properly now, and its apparently not something obvious enough to be clear over and "internet diagnostic".

Get the gun to someone who knows the gun, inside and out and have them look it over.

AND don't expect to get good answers from U tubers. For every real expert out there, there hundreds who just sound like they are.

consider getting an old copy of Small Arms of the World (old editions are often fairly cheap) there are pictures and things in there that might be useful and not in the Army manuals.

Good Luck!

 

[Nodak1858]

Did you have issues before adding the new op-rod spring?
Was is a USGI or equivalent or did you put in an "extra" power one?

 

[nhyrum]

Did you have issues before adding the new op-rod spring?
Was is a USGI or equivalent or did you put in an "extra" power one?

Yes, I had issues before replacing the oprod spring. Standard usgi replacement.One of the troubleshooting pages I read mentioned the spring being a common failure point

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[jcj54]

M1 short stroking

The rifle is definitely short stroking due to gas leakage as you state it is properly lubed.
The magazine is not the problem.
The four areas that tha cause this are:
1) undersized gas piston on the op rod
2) gas cylinder bore worn oversize
3) barrel diameter where gas port is and gas cylinder fits is worn and allows gas leakage
4) gas cylinder plug valve is not sealing

Your rifle demonstrates classic symptoms of gas leakage due to one or more of these things. As it functions some of the time and does eject but not pick up the next round when the failure occurs the parts are definitely worn and it is likely a tolerance stackup.

You state it worked fine until you disassembled and cleaned it. Carbon/powder residue on the barrel where the gas port is will act to reduce gas leakage as it will in the gas cylinder bore. Once the carbon residue is removed gas has a path to travel and will leak causing short stroking.

You have reached the point where you either take the rifle to someone who has the tools to check the parts or begin changing the parts mentioned, op rod, gas cylinder, and gas plug.
Known good gas cylinders are available as are known good op rods, neither are inexpensive.

As I stated, I have worked on M1 rifles for 35 years and have seen this exact problem many times. Usually it is either a worn piston, worn gas cylinder, or both.

 

[HiBC]

Tried changing the position of the gas cylinder lock, from one to two turns backed off. Two turns seemed to work best.

I'm not too sure about that.

 

[44 AMP]

The rifle is definitely short stroking due to gas leakage as you state it is properly lubed.
The magazine is not the problem.

I am not convinced of this, based on the OP's description. SO, some clarification is needed.

The rifle, as it currently operates does what??

When you insert an 8 rnd enbloc clip of M2 ball, it chambers the first round, normally, yes/no?

When you fire that round, it extracts and ejects normally, but the bolt closes on an empty chamber yes/no?

manually working the action then chambers the next round ?

DO ALL rounds in the clip do that, or only some of them? I get the impression that the rifle works right with the last two (or maybe 4?) rounds in the clip. Is this correct?

Does it eject the empty clip and lock open properly when empty??

Based on what I know right now, the rifle COULD be short stroking, with the bolt coming back enough to eject the fired case but not quite far enough to pick up the next round and chamber it. IF that is the case, then it is a gas problem.

however, gas problems tend to be pretty consistent, SO, if its not doing it with every round in the clip, it might not be a gas problem.

Bolt override COULD BE caused by the tension of the follower. IF the follower does not lift the rounds up fast enough so the top one is in proper position to be picked up by the bolt moving forward then the bolt closes on an empty chamber.

IF the last couple or last few rounds in the clip DO feed properly that indicates that the follower lift pressure is marginal, enough to lift the last couple rounds in time, but not enough to lift the full clips rounds before the bolt closes over them.
From the pictures I have it appears that it is the op rod spring that powers the follower system.

So, the possibilities there are, weak spring, (unlikely with a new spring), incorrect assembly of the mechanism in some fashion, or binding caused by something else. Bent, worn parts, or possibly foreign debris in the mechanism. (which is why I don't store guns with the action open)

Generally speaking, worn, damaged / out of spec parts don't work some of the time generally they don't work all the time, but that is not a set in stone rule. If they work some of the time it will generally be in a pattern, such as only malfunctioning when the clip is full, but working ok when its nearly empty, for example.

If you want to keep tackling this yourself, I would suggest carefully studying your reference material, then disassembling the rifle again, and then carefully reassembling it by the numbers (written instructions) then test firing with GI Ball (M2) not handloads (as a QC step) and seeing if it works properly or not.

Also, I would suggest getting several clips to test with, so as to rule out the possibility your problem is a defective clip or two.

IF that works. you're good to go. IF not, you've done all you can do and its time to seek the aid of a expert, amateur or paid professional, your call.
Good Luck!

 

[nhyrum]

I am not convinced of this, based on the OP's description. SO, some clarification is needed.



The rifle, as it currently operates does what??



When you insert an 8 rnd enbloc clip of M2 ball, it chambers the first round, normally, yes/no?



When you fire that round, it extracts and ejects normally, but the bolt closes on an empty chamber yes/no?



manually working the action then chambers the next round ?



DO ALL rounds in the clip do that, or only some of them? I get the impression that the rifle works right with the last two (or maybe 4?) rounds in the clip. Is this correct?



Does it eject the empty clip and lock open properly when empty??



Based on what I know right now, the rifle COULD be short stroking, with the bolt coming back enough to eject the fired case but not quite far enough to pick up the next round and chamber it. IF that is the case, then it is a gas problem.



however, gas problems tend to be pretty consistent, SO, if its not doing it with every round in the clip, it might not be a gas problem.



Bolt override COULD BE caused by the tension of the follower. IF the follower does not lift the rounds up fast enough so the top one is in proper position to be picked up by the bolt moving forward then the bolt closes on an empty chamber.



IF the last couple or last few rounds in the clip DO feed properly that indicates that the follower lift pressure is marginal, enough to lift the last couple rounds in time, but not enough to lift the full clips rounds before the bolt closes over them.

From the pictures I have it appears that it is the op rod spring that powers the follower system.



So, the possibilities there are, weak spring, (unlikely with a new spring), incorrect assembly of the mechanism in some fashion, or binding caused by something else. Bent, worn parts, or possibly foreign debris in the mechanism. (which is why I don't store guns with the action open)



Generally speaking, worn, damaged / out of spec parts don't work some of the time generally they don't work all the time, but that is not a set in stone rule. If they work some of the time it will generally be in a pattern, such as only malfunctioning when the clip is full, but working ok when its nearly empty, for example.



If you want to keep tackling this yourself, I would suggest carefully studying your reference material, then disassembling the rifle again, and then carefully reassembling it by the numbers (written instructions) then test firing with GI Ball (M2) not handloads (as a QC step) and seeing if it works properly or not.



Also, I would suggest getting several clips to test with, so as to rule out the possibility your problem is a defective clip or two.



IF that works. you're good to go. IF not, you've done all you can do and its time to seek the aid of a expert, amateur or paid professional, your call.

Good Luck!

8 round clips insert fine, the bolt releases fine, it just takes a little bump on the charging handle to get the round to feed. It's always done this and have heard it's normal. So, I'd say the first round feeds fine.

On firing, the spent case extracts and ejects normally, and the bolt closes on an empty chamber. A normal rack of the charging handle feeds a new round. I've tried to do it as quick as I can to mimic how fast it would move under normal operation, but of course I can't move it that fast. Nothing hangs up, etc.

Not every round will fail to get picked up. It's maybe the first 4 or 5 that fail, the rest will work. Clips don't fully eject, most the time, after firing the 8th round I need to manually work the action to get the clip to eject. It didn't do this before.

I do have about 15 clips to test with

It very well could be that I have something together improperly.

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[44 AMP]

Giving the op rod handle a little bump to get it to close after loading a clip is normal. It is the way it is supposed to work. Guns that shut without needing the bump are what causes the painful injury known as "M1 thumb".

Working the way you describe, I'd say its NOT a gas problem, its a feed system problem.

Exactly what, you'll have to figure out.

Good Luck

 

[tangolima]

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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