Barrel twist and suppressor thread handedness

[GenePoole]

I've got a SIG P239 barrel a friend want's threaded for a suppressor mount. It's about 3/4 inch longer than the factory barrel. The factory SIG setup for this, as I understand, came with a 13.5x1.0mm LH thread. I practiced a few of these from the AAC print(1) on some stock and was confident I could do the job. He gave me the gun and new barrel (it needed some fitting too) and while examining the two barrels, I noticed that the handedness of the rifling of each was opposite. The new barrel was of unknown origin, but marketed as unthreaded so as to use a more convenient thread such as 1/2-28 (Right-hand).

In short, is there any relationship between the handedness of the rifling and that of the suppressor threads that I need to account for?

1. http://www.advanced-armament.com/assets/images/pdf/manuals/ThreadGuideREV_01-040513.PDF

 

[Dusty Stevens]

Ive noticed half the pistols of european toots have lh twist barrels. I dont think it matters as i have an HK usp tactical that has a thread one way and a mark 23 which is the exact same model except their higher end that has the opposite threads. Both are metric and both have lh twist barrels just opposite threads. Maybe its a mil spec type thing over a consumer model in who makes the military suppressors and what thread they have

 

[orbitup]

I have barrels with both kinds of threads. As long as the piston fits it'll work.

 

[carlsbad]

I don't know for sure, and don't want to research it since threaded barrels on pistols are illegal in CA, but it might be that you want the twist on a barrel opposite the threads on the suppressor so that the torque from the bullet going down the tube tightens the suppressor rather than loosens it. So for right hand thread I'd use a left twist barrel.

--jerry

 

[butchlambert]

My latest Rim Firebarrel is a LH tw.

 

[JRS]

Right or left makes no difference. The suppressor isn't going to unscrew itself.

The bullet doesn't touch the suppressor.

 

[Eddie Harren]

I don't know for sure, and don't want to research it since threaded barrels on pistols are illegal in CA, but it might be that you want the twist on a barrel opposite the threads on the suppressor so that the torque from the bullet going down the tube tightens the suppressor rather than loosens it. So for right hand thread I'd use a left twist.



So, Jerry the Engineer, your suppressor is rifled?

 

[butchlambert]

Right or left makes no difference. The suppressor isn't going to unscrew itself.

The bullet doesn't touch the suppressor.

I don't have a suppressor, my LH will just tighten the tenon. Hopefully it won't unscrew itself and fall off.

 

[Dans40X]

OP,
Tell your buddy to purchase a 239 Bbl from SIG SAUER that is threaded 13.5x1LH & is a direct replacement w/adapters/thread protector, that will drop into the slide for $230 & there are currently 9 on hand at SIG SAUER.

 

[GenePoole]

Where's the fun in that?

It's done anyway.