A thread about threads!

[longcruise]

Well, specifically the threads for the cleanout screw on a GM drop in barrel.

I lost mine while doing a barrel refinish and nothing in my treasure chest seems to fit. Any help here appreciated!

 

[SmokepoleSam]

I just checked my two Green Mountain barrels and one is 8/32 and the other is10/32 threads. Go to your local hardware store with the barrel and try some screws, or buy a few screws and take them home to try. Your jags and brushes are 8/32 or 10/32 so you could try them also. Good luck

 

[SDSmlf]

FYI, not really a clean out screw, just the plug for the cross drill hole required to connect the nipple hole to the breech. TC actually started drilling from the opposite side of the barrel specifically to stop people from removing the screw and losing it or buggering it up.

There is is no good reason to remove the screw.

 

[longcruise]

FYI, not really a clean out screw, just the plug for the cross drill hole required to connect the nipple hole to the breech. TC actually started drilling from the opposite side of the barrel specifically to stop people from removing the screw and losing it or buggering it up.

There is is no good reason to remove the screw.

Yeah but clean out screw is commonly understood and more economical than
"FYI, not really a clean out screw, just the plug for the cross drill hole required to connect the nipple hole to the breech."

Actually I had a very good reason for removing it but unfortunately lost it. Thought I'd solve the problem without carrying a gun barrel into the hardware store but that's probably what I'll do in the morning.

 

[bubba.50]

As stateed, you can try your cleanin’ jags and take whichever size works to the hardware store. Be easier than totin’ a barrel.

 

[longcruise]

I had a bunch of screws to play with and determined 10-32. They were all allen heads and I wanted a flat screwdriver head so I picked one up at Ace.

Interesting observation, the threads have a very slight taper. Probably intentionally done with a through tap. It allows a tight fit with the correct length screw and doesn't allow the screw to go up against the nipple threads. If a too long screw were forced it could jam into the nipple threads.

 

[SDSmlf]

I had a bunch of screws to play with and determined 10-32. They were all allen heads and I wanted a flat screwdriver head so I picked one up at Ace.

Interesting observation, the threads have a very slight taper. Probably intentionally done with a through tap. It allows a tight fit with the correct length screw and doesn't allow the screw to go up against the nipple threads. If a too long screw were forced it could jam into the nipple threads.

There was an issue reported with some GM barrels having the ‘clean out screw’ going in too deep and causing problems with some nipples. Sounds like you don’t have that issue, but something to be aware of.

 

[ugly old guy]

Have you asked Green Mountain?
They should know. They might even have a replacement in stock they'll send you for little or nothing.

 

[longcruise]

Per post #6, problem solved.