M1 Garand - Help! Wobbly Gas Cylinder

[johnmcl]

Hi guys,

So I detailed strippped and cleaned my IH M1. The rifle came apart and went back together just fine with one exception. I notice the gas cylinder is just slightly loose. Now since the sights are attached (of course) to the gas cylinder this very small wobble is very big news.

The gas cylinder lock won't go around another rotation. I also think the gas cylinder screw valve is in deep.

Has anyone seen this condition before and what I can do to correct?

Lemme know,

John

p.s., the IH's cousin, a beautiful dark HR, just came from CMP. Looks wonderful except they stay up all night talking....

 

[FALna45]

PEENING may be in order

 

[Steve in PA]

How "loose" is loose?? Very visible, or do you really have to look at it to notice.

The gas cylinder on my M1 is "slightly" loose, by that I mean barely enough to notice any freeplay. I get very good accuracy out of it.

You can peen the spines on the barrel (where the cylinder slides over). One way is to use, I think it was a 1/2" socket laid on the spines and tap the socket with a hammer, basically you are peening the edges of the spines in. Then when you slide the cylidner on, it will fit alot tighter.

Only do a little at a time on all three spines. Some people have also cut shims from aluminum cans.

Do a search on some of the Garand boards and you'll fine a more detailed explanation on peening and shimming.

 

[30Cal]

Pretty normal for a service grade rifle. You can peen the splines to tighten it up, but if you remove the gas cylinder all the time, it'll loosen.

Thread the gas cyl lock all the way down. If it stops at 5 o'clock, then continue till 6 o'clock and screw in the gas plug. Otherwise, back the gas cyl lock as necessary to get the gas plug in. On a match grade rifle, you would want to hand-select a gas cyl lock that times between 5 and 7 o'clock.

Ty

 

[jefnvk]

Did it just come from CMP? They will fix it.

 

[Guy B. Meredith]

I do believe I saw a thread on this and mention that a certain amount of play is normal. Check with the CMP.

 

[30Cal]

It's not one of their reject criteria. It will not adversely affect function, but isn't helpful for accuracy. On non-match rifles, it's perfectly normal.

Ty

 

[cracked butt]

Peen the barrel splines, but becareful a little peening goes a long way.
Mine was loosey goosey when I got it, now the cylinder is rock solid.

 

[grendelbane]

Peening will work. For the more cowardly among us, Loc-Tite will also work.

It is a quick and dirty fix, but it will work.

 

[Swampy]

It's not one of their reject criteria. It will not adversely affect function, but isn't helpful for accuracy. On non-match rifles, it's perfectly normal.

+1.

The M1 was designed around corrosive ammo... and the GI or Marine using it had to be able to get the gas cylinder off in the field for cleaning.. hence the looser tolerances.

Best to all,
Swampy

garands forever

 

[johnmcl]

Will Try Peening

Hi all,

Well, I do not have it clear in my mind on whether peening or shimming is the path forward. I will scan the Garand boards (any recommendations?) first. I'll probably first shim with an aluminum strip. If that's unsatisfactory in form or function I'll then try a peening. That peening will go gently, and I do mean *gently*.

Let me answer the questions put forward so far in this thoughtful thread. First, the gas cylinder is only slightly loose. By holding the rifle still I can only notice a slight degree of looseness on the cylinder. This is what raised my concerned as I remember reading in Duff's book that 0.08 in movement of the front sight will cause a 1 in movement in POI.

The cylinder lock stops tightening at the 7 o'clock position. If I could screw it down there it'd be wonderful tight.

This rifle is not a CMP. I bought this IH back in the 80's overseas. The IH has a SN of 4583733 with a great LMR barrel. My recently arrived HR however is a CMP. The HR gas cylinder has no movement.

Thanks guys,

John

 

[Crosshair]

I shimmed my Garand with some very thin hobby wire. Works great.

 

[Steve in PA]

Don't worry about cranking the lock down too tight. You want some free play in the front handguard. If it goes to 7 o'clock, just back it off to 6 o'clock and tighten the screw. My lock goes to 10 o'clock and it shoots just fine. If you crank the lock down too far you'll bind up the front handguard and your accuracy will really suffer.

Just make sure the gas port in the bottom of the barrel is centered in the small opening in the gas cylinder, then tighten the screw.

If your front sight only moves that little I wouldn't worry about.

As for what "Garand" boards, these are my usual stops;

CMP Discussion Forum

Guntalk

Your American Backyard Forum

Surplusrifle

I have several more but these should keep you busy for awhile.

 

[TheEgg]

The critical question is "how does it shoot"? If it shoots as well or better than you can, leave it alone. If it adversely effects accuracy (IMHO, it probably won't), peen it.

 

[30Cal]

1MoA = 0.008" of sight movement.

Ty