My Garand doesn't cycle, and I think its the gas tube

My Garand doesn't cycle.* Bolt is not stripping a fresh round from the clip.* Chamber is empty.* Piston is .5248/.5247 (two measures 90 deg apart), so a little under .525.* Cylinder accepts .528 pin, pin slides through freely.* .530 pin does not go in either end. Bore gauge measures .5285/.5286 at the muzzle* So the piston is slightly small, but the cylinder is well under .532, so the clearance isnt bad.* Bore is clean and shiny except for a dull* area* near the sling swivel that extends about an inch into the bore.* Bore measures*.529/.545 at the sling swivel.* Looks like machining marks in this area from a twist drill or a boring bar.* Gun worked well until a long day at the range.* Went home, gave it a serious cleaning and it hasn't worked since.* My guess is gas is venting before the bolt gets behind the top round.* My thought was the wear slowly filled with carbon enough so that it cycled normally, then I cleaned it and no joy.* But the* machining marks are a mystery.* Doesnt look like wear marks, and no scraping on the piston. Is that wear, or is that original, or what? Is my gas cylinder junk?

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Originally Posted by RickFischer51

Looks like machining marks in this area from a twist drill or a boring bar.

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That part is so the op rod can move freely, it takes a dip at the back end when at the rear.

Is the gas cylinder in the correct spot? Is the gas port open to the vent in the gas cylinder?

Hey Steve and Jim, thanks for the replies.

Regarding Steve's input:

1. Gun is clean and well lubed. Think Private Pyle and his Charlene fetish. I use Wilson Combat grease on everything except the op rod, which gets lubriplate. I've wondered about the ammo. I have Lake City and some 3rd world NATO stuff, cant remember when I acquired the NATO stuff in relation to when the problem started, but I will definitely take a variety with me next time I go. Haven't paid attention to the clips until lately. Read about one brand that is junk, I dont have those. Last friday I used AEC clips with the NATO ammo. No luck. There is a thread on CMP about AEC clips, one guy says they're junk, other guys say they're great. I have other brands an will try them.
2. Plug is unvented.
3. I pass the 60 deg tilt test with flying colors.
4. Didnt know about the roll pin. Ill check it.
5. Plug is tight. Threads are clean, and I have the wrench and the holder that fits on the cylinder lock.
6. Spring is greased. I think the op rod is clean on the inside, but ill check it again.
7. I replaced the op rod spring with an Orion stainless steel spring. I'm making a fixture to measure spring loads on the new and original springs.

Per Jim's comment, so that gouge in the bore is normal and in fact necessary? Great! The gas cylinder seemed to be in nice shape otherwise with a lot of life left.

I'm gonna try and get out again this Friday and try different ammo and clip combos. If its the ammo, I guess that gets relegated to my Springfield. Thanks again for the help guys.

---------- Post added at 06:09 AM ---------- Previous post was at 06:07 AM ----------

Oh yeah, I forgot. Gas port is clean. Shank of a #47 drill fits, a #46 doesnt.

One common problem is alignment of the gas cylinder with the gas port in the barrel. On a number occasions I have had customers who had the same problem it turned out to be that the gas cylinder tighten too far back on to the barrel with the gas cylinder partially blocking the gas port thus not providing enough gas pressure to fully cycle the rifle. I use a common bent paperclip to ensure that the gas cylinder is properly aligned with the gas port before tightening the gas lock to the barrel and gas cylinder.

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Originally Posted by RickFischer51

that gouge in the bore is normal

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Yes.

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Originally Posted by fjruple

One common problem is alignment of the gas cylinder with the gas port in the barrel.

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That's what I was pointing out too.

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Originally Posted by RickFischer51

I replaced the op rod spring with an Orion stainless steel spring

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I could recommend using GI springs, the replacements don't always measure up correctly.

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Originally Posted by RickFischer51

I have Lake City and some 3rd world NATO stuff

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That's a possibility too. Use good source ammo or load your own.

US military original clips are best. They usually cause a different stoppage though, yours sounds like insufficient gas.

I am no expert by any stretch of imagination as I have only dismantled and reassembled my Garand one time. When I first received it from CMP, I stripped it down completely, documented the parts diagram numbers, cleaned, lubed and oiled everything, then reassembled it. The rifle has always worked perfectly and helped to "ping" about 30 new M1 shooters. I think the key to your problem is that it worked fine until you took it apart and then reassembled it. That would tell me that something didn't go right during it's reassembly. I recommend you take it apart again, find a good YouTube video that walks you through the assembly process, reassemble it, then see what happens. I have had it happen to me several times during projects where I missed something during the assembly process, had to research what I missed and then redo it. Besides, it is actually kind of fun and relaxing to work on a beautiful rifle like that!

"...Bolt is not stripping a fresh round..." That can be the clip, the clip latch. If you have an inside micrometer, measure the gas tube diameter. It dopes sound like a reassembly issue though. Much preferable to any part replacing thing.
There's a free, .pdf manual here. Note the need for the provided UN & PW.
Biggerhammer.net - Miscellaneous Firearms Technical and Training Manuals

Like you read over on the Garand forum, you gas cylinder is reject at 0.525”. Also one should not have a shiny gas cylinder.

Just to satisfy my Puritan background, could we change the thread title from "gas tube" to the proper "gas cylinder"?

My cylinder accepts the .528 pin and measures almost .529

Problem solved. Lame ammo. Lake City and Twin Cities cycles just fine with any brand clip. The lame stuff doesnt work with any clip. Head stamp is weird, cant find it listed, pic is attached. I guess thats reallocated to my Springfield

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Originally Posted by browningautorifle

Use good source ammo or load your own.

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Originally Posted by RickFischer51

Problem solved. Lame ammo. Lake City and Twin Cities cycles just fine

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Thought as much...

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Originally Posted by browningautorifle

Thought as much...

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Hey BAR, is that Ethiopian 30 -06? I have never seen a head stamp like that

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Originally Posted by jond41403

is that Ethiopian 30 -06

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I don't think so, here's Ethiopian... Maybe Syrian, Egyptian?

It's actually Iranian. Made in (19)44, as you can tell (you can tell, can't you?:madsmile: ) from the 44 in Farsi lettering at the bottom - At the top there is a crown to give the orientation.

No joke! You can find it on MUNICION.ORG if you look through the dozens of 30-06 headstamps.

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Originally Posted by Patrick Chadwick

It's actually Iranian.

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Good...

Almost certainly that krap ammo has corrosive primers. MAKE SURE you detail clean the rifle for corrosive ammo or you could regret it.

I don't know what's the problem is "but Bolt is not stripping a fresh round" i think your problem is the clip..

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Originally Posted by AlexRod85

i think your problem is the clip..

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If you read the whole thread, he gives the solution he found in post #11...

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Originally Posted by RickFischer51

Problem solved. Lame ammo. Lake City and Twin Cities cycles just fine with any brand clip.

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