Can a barrel be rethreaded?

[twolane]

So, question to the gunsmiths out there... Can a barrel that came from the factory without a thread, and was threaded, be rethreaded to a smaller, more common size?
I know I could use a thread adapter (I assume Rockset would be the best choice there) but before I go that route, I'd like to know for sure what my options are.
Thanks!

[deadshot2]

The answer to your question is going to depend on what the make and caliber of the rifle the barrel was "threaded" for, which end you're talking about (breech or muzzle), and what the new thread pitch will be.

Do you want to move the barrel to another rifle? Or are you talking about threads for muzzle devices. If Muzzle end, good chance you can go smaller. Breech end, not an easy task because of how one change can cascade into more changes.

[twolane]

Muzzle end.

The barrel is bored for 38 special. It was threaded by the machinist in 9/16x24 due to some miscommunication and I would like to have it done at 1/2x28.
I'm worried that only taking off an 1/8 and changing the thread pitch will be a no go.

[mcyclonegt]

This chart is showing the minor diameter or the root diameter of 9/16x24 as .5117. Basically if you turned the threads off, they would disappear at this diameter. 1/2x28 is an odd size and is not on this chart, but it will be .5 or less. So yes, it can be turned down and rethreaded.

http://www.engineersedge.com/screw_threads_chart.htm

[deadshot2]

You're going to have a problem with insufficient material if you cut your barrel down to 1/2-28 threaded end. That's a fine size for a .22 cal (AR, etc).

That works out to .138" or so per side ON A .224 bullet sized bore. You said 38 special so that would be .357". You lose another 1/16" inch on each side

By my estimate, using charts I have available, you'll have a wall thickness on the barrel at the muzzle (after cutting and threading) of only 1/8".

Either leave it where it is and get your muzzle device built to fit the 9/16" threads or change barrels. The barrel should have been threaded for a 5/8" muzzle device at that caliber.

Depending on the device, you might have it drilled out and re-tapped/threaded to the 9/16" threads you have.

[MadPick]

You're going to have a problem with insufficient material if you cut your barrel down to 1/2-28 threaded end. That's a fine size for a .22 cal (AR, etc).

1/2x28 and 1/2x36 are standard thread sizes for 9mm (.355) . . . for what that's worth.

[deadshot2]

You're going to have a problem with insufficient material if you cut your barrel down to 1/2-28 threaded end. That's a fine size for a .22 cal (AR, etc).

1/2x28 and 1/2x36 are standard thread sizes for 9mm (.355) . . . for what that's worth.

I kind of live in the world of rifles so I overlooked that.

[twolane]

Thank you all.
I have the answers I need and should be good to go. Wish me luck with the 'smith.

[cdoniguian]

OK, good luck!

[3584ELK]

Thank you all.
I have the answers I need and should be good to go. Wish me luck with the 'smith.

May I ask to whom are you taking the work?

[TacticalAssault]

Hope you got it done right. It needed to be turned on a lathe. Using a sanding drum on a dremel and going around it is NOT the way. LMAO.