M305 Norinco Gas Plug Issue

[Travis Bickle]

My trusty old Norc M14 shoots like a demon.
Moderate tweaks done by myself, indexed the barrel, swapped the rear sight for usgi, shimmed the gas system, have a Boyds walnut stock on her (M1A), swapped the flash hider as the original was cast offset lol
Shoots awesome for a sloppy gas operated battle rifle.
Only issue is after I shoot a couple rounds, the gas plug that threads into the gas block comes loose.
It obviously won't fall off as it's threaded 100 turns or whatever but it does come loose/backs itself out without fail every time I shoot it.
It did it before I tweaked the rifle.
It still does it.

Anyone else have this issue, know what's causing it, or have a suggestion for a fix that doesn't including buying a Springfield?
Any help would be appreciated.

 

[ipscgraz]

What torque are you applying to the gas plug on installation.

If memory serves, it has to be substantial or the GP will vibrate loose quickly.

 

[yomomma]

IIRC it should be about 125 in/lbs

 

[Travis Bickle]

IIRC it should be about 125 in/lbs

Holy s**t!
Really?!
I guess I better put some M-A-N on it then
I usually hand torqued it then used the butt stock tool to hand tension it but nowhere near that much force.
So basically I'm just being a pussy and need to wrench down on that thing with some serious force?

 

[Andy]

That's 125 in-lbs, which is about 10 ft-lbs. Not much really.

 

[machman]

Happens to mine to, I use a dab of blue Loctite.

 

[LeftFootOfDoom]

yes, happens on both of mine and guys that i know. The recoil/vibration of shooting does it, then you will have short cycling due to insufficient gas. You probably will not be capable of tightening it enough by hand, I had to get one of the gas block wrenches to work with the regular cleaning rod handle/wrench so i could get enough torque to keep it tight. I dont know what those guys did when they were in combat.

 

[ipscgraz]

I find it difficult to apply sufficient torque with the rifle wanting to squirm around. I place the M 14 tool on the gas plug, and lay the rifle onto the floor, then push down on the barrel assembly to tighten the gas plug. Same to undo.

Please do NOT confuse inch pounds and foot pounds!

 

[45ACPKING]

my old military handbook that was issued to each soldier getting one of these rifles back in the 60's says to use a flat blade screwdriver between the barrel and tube of the gas cylinder...... YIKES
let's not do that outside of a shtf scenario LOL
stand rifle up, brace stock and action between feet and knees and torque away.
one trick I found with those self loosening gas plugs is IF you have a nice tight gas lock, thread in and torque the plug till tight. then give the gas lock itself another nudge with the gas lock wrench to bump it against the plug inside.
works for me. I have a all USGI parts one that does it too.

 

[Travis Bickle]

Interesting.
Seems it's a very common issue with the design in general regardless of make/manufacture.
I don't want to loc-tite it every time. It would be a pain and start getting pretty crusty in the threads after so many applications I would imagine?
Good to know it's not just mine though.
45ACP, my gas lock is nice and tight, I shimmed it so it tightens up at the "4-5 o'clock" position and then take considerable hand force to turn it the rest of the way until I can drop the plug in. I will try to torque it just a hair past after I thread in the plug.
Thanks for the tip!

 

[Hitzy]

I also use loctite and never had an issue. Use it on the M1 as well.