One final question about M1 Carbine piston nut

[Mr_Flintstone]

I have an Auto Ordnance M1 carbine that I've posted about before. The gas piston nut kept coming loose. I've tried tightening, blue Loctite, and a light stake. It kept coming loose. Yesterday, I decided to do a heavier stake, and I accidentally let the punch slip on the first hit. It made a dimple in the piston nut recess where the stake metal is supposed to go. Although it is not what was supposed to happen, it did lock the piston in place. I ran a whole box of ammo through it at a high rate of fire, and checked again. It was still holding in place like it should.

Now my question. Since the nut is holding, and the piston is moving freely, should I worry about possible damage to the threads on the gas block? I know it will probably never need to be removed again unless something out of the ordinary happens.

 

[Carl N. Brown]

In 1990 I bought an M1 Carbine made by IBM in 1943, reimported from South Korea by Blue Sky Virginia.
I also bought a repro of the Army/Air Force tech manual on the M1 Carbine.
The piston nut on my gun is heavily staked in place, probably at the last arsenal recondition before being put in reserve in Korea.
The punch stake for the piston nut is not dainty. It does not walk loose. I have fired the gun thousands of rounds without bothering the nut or piston. I suspect that, if the places making commercial M1 Carbines made memorizing the Army/Air Force tech manual mandatory for their assemblers, there would be fewer complaints about their finished product. Like piston nuts walking out under normal use.

If yours is staying in place now, "it will probably never need to be removed again unless something out of the ordinary happens."
It is a semi-permanent assembly for the typical life of the gun, like the slide catch of the CZ-52 or the riveted forearm and liner of the ArmaLite rifle. Once assembled properly, should stay assembled.

The carbine is designed to be self cleaning when used with non-corrosive primed ammo; all U.S. issue and commercial ammo in .30 carbine is non-corrosive primed.* The tech manual advises keep it dry: clean the gun "upside down" so solvent and sludge does not get down the vent hole into the piston chamber and the gas system will self clean in normal use.
(Similar tale: If people had run the M1000 Howa/S&W/Mossberg gas operated shotgun piston dry, there would not be the horror stories of it sludging up.)
_________________________
* The French after WWII made a delayed roller block CETME style carbine (not gas operated) and thought it was a good idea to use corrosove primers (!?); it has largely disappeared from the surplus market.

 

[Mr_Flintstone]

In 1990 I bought an M1 Carbine made by IBM in 1943, reimported from South Korea by Blue Sky Virginia.
I also bought a repro of the Army/Air Force tech manual on the M1 Carbine.
The piston nut on my gun is heavily staked in place, probably at the last arsenal recondition before being put in reserve in Korea.
The punch stake for the piston nut is not dainty. It does not walk loose. I have fired the gun thousands of rounds without bothering the nut or piston. I suspect that, if the places making commercial M1 Carbines made memorizing the Army/Air Force tech manual mandatory for their assemblers, there would be fewer complaints about their finished product. Like piston nuts walking out under normal use.

If yours is staying in place now, "it will probably never need to be removed again unless something out of the ordinary happens."
It is a semi-permanent assembly for the typical life of the gun, like the slide catch of the CZ-52 or the riveted forearm and liner of the ArmaLite rifle. Once assembled properly, should stay assembled.

The carbine is designed to be self cleaning when used with non-corrosive primed ammo; all U.S. issue and commercial ammo in .30 carbine is non-corrosive primed.* The tech manual advises keep it dry: clean the gun "upside down" so solvent and sludge does not get down the vent hole into the piston chamber and the gas system will self clean in normal use.
(Similar tale: If people had run the M1000 Howa/S&W/Mossberg gas operated shotgun piston dry, there would not be the horror stories of it sludging up.)
_________________________
* The French after WWII made a delayed roller block CETME style carbine (not gas operated) and thought it was a good idea to use corrosove primers (!?); it has largely disappeared from the surplus market.

Thanks. I figured it would be OK, but I thought I'd ask to make sure.