problem with my m1 carbine gas system

[greyling22]

I think I may need the M1 Carbine Gas Cylinder Tool Set, as seen here https://www.standardpartsllc.com/productcart/pc/viewPrd.asp?idproduct=126
Does anybody have one they would loan me? I will pay shipping both ways.


Here is the deal: I shoot lead through my inland m1 carbine, I know it's not designed for it and lead and gas guns don't go real well together blah blah blah. After a while I began having ejection issues, so I popped it all apart, broke the gas piston nut loose from the staking and removed and cleaned it and the piston, cleaned out the lead from the gas port and cylinder, then put it all back together and it worked great.
A few years go by, and I begin to have ejection issues again. I pull it all apart, clean out the lead deposits, and put it back together, paying careful attention to not crossthreading the piston nut and.......... I crossthreaded it. So I backed it out and tried again and the threads on the nut are just bunged up. The threads inside the gas cylinder look fine (whew) So I got to thinking that maybe the original staking may be part of the crossthreading issue, because at no point ever has it been easy to move that nut in or out. I was thinking try and clean up the threads in the cylinder, buy a new piston nut, and give it another go. The only way I know of to clean up those threads is to use the tool I linked above, and I would sure rather borrow or rent one than buy one. They are spendy. Am I barking up the wrong tree here? Do I just need to try a new nut and forget attempting to clean up the threads of any possible issues?

Attached are poor quality phone pictures, and there is an ultimak scout rail bolted on the barrel, so that is what looks funny.

 

[Maj Dad]

Swiss Files and Loctite

A thread chaser would be fine, but your threads don't look to be really damaged. I would think you could use small Swiss-pattern files (I used them on mine) to knock those burrs off & it should be o.k. I shoot lead bullets in one of mine, and I use plain old blue loctite after cleaning it all out & it holds just dandy. I was going to go whole hog on all the tools, but a little birdie whispered in my cheap ear to try the loctite, and it worked. Beats $150...

HTH

 

[Jim K]

If the nut is visibly damaged, I would buy a new one, then do as Maj Dad suggests rather than staking it. DON'T tighten it all the way down; the reason they were staked is that the right point is not down tight, but (at least on the GI guns) with the bottom of the nut cuts even with the rear of the cylinder. Then, install the new nut by hand to be sure it doesn't crossthread. If it does, don't force it. You will need a thread chaser for the cylinder.

BTW, do you use gas checks on your bullets? They might help prevent most of the leading.

Jim

 

[carbine85]

The proper tap to use is called a bottom tap. I have one around here somewhere. If I can find it I'll provide the specs or don't mind lending it to you. I bought from McMaster Carr. I just haven't seen in it a few years. If you working slowly and pay attention you can chase the thread without the whole tool set. In my experience it's always the first 1 or 2 threads that are the problem and the piston nut gets hacked up from the stacking. Buy a new piston nut.

 

[greyling22]

maybe the new piston nuts I have ordered will thread on my hand, (and I will try and knock those burr's off) but as it sits right now, I have been unable to get the nut to turn at all without the wrench.

I do not use gas checks, can't afford them and my mold does not support them. Gun shoots accurate and doens't lead up the barrel, but after 500 or 1000 rounds I begin to have cycling problems. A little cleaning seems to clear it right up, and if I can get the nut to come in and out smoothly it won't be a big deal at all to clean it out. I don't have any small round files, but I bet I could improvise with some 320 grit sandpaper and a small dowel rod.

 

[carbine85]

maybe the new piston nuts I have ordered will thread on my hand, (and I will try and knock those burr's off) but as it sits right now, I have been unable to get the nut to turn at all without the wrench.

I haven't ever tried without the piston nut wrench. It's usually stiff most of the way out. I work them back and forth with oil. Do you have the correct wrench?

 

[greyling22]

yes, I have the wrench. Jim's post made it sound like it should just thread right in thereby hand, like putting a 1/4" nut on a bolt from home depot, and that has not been my (limited) experience.

 

[rcmodel]

but I bet I could improvise with some 320 grit sandpaper and a small dowel rod.

Oh, Don't do that!!!

First thing to try is, chuck a bronze bore brush in a drill and using bore solvent, clean the crap out of the threads with that.

They are likely gummed up with carbon and lead fouling all the way to the bottom..

rc

 

[greyling22]

new nut and new piston installed just fine. (I ordered 2 nuts but they sent me a piston and a nut so I figured enh, why not. That's what you get when ordering by phone while driving down the highway in bad reception)

the new piston slides more freely like it is supposed to.

 

[carbine85]

new nut and new piston installed just fine. (I ordered 2 nuts but they sent me a piston and a nut so I figured enh, why not. That's what you get when ordering by phone while driving down the highway in bad reception)

the new piston slides more freely like it is supposed to.

The manuals tell you to replace both at the same time so that's actually the proper way to repair it.
Make sure you re-torque after you shoot it. They will come loose and damage the gas block if it's not staked.

 

[JR47]

There were actually more than one gas-piston nut used. The later versions actually gave the piston a little more travel, for use in the M2 Carbine. While you're cleaning everything up, have you made sure that the gas-port from the barrel is clear and clean?

 

[greyling22]

Using m2 nut. Gas port is clear. I used a small drill bit with my fingers.

 

[velocette]

Good place for M1 Carbine information :
http://forums.thecmp.org/forumdisplay.php?f=6

Roger