I've decided my next build is to be a 9mm AR. Particularly one of a more retro flavor. Not necessarily a direct clone, mind you.

It seems that doublestar makes a barrel that would suit my needs, outside of finding an old Colt SMG parts kit. Those seem to have dried up, however.

LINK

Aside from it currently being backordered, they don't appear to list what threads the muzzle are. I would assume 1/2-36, or 1/2-28.

Does anyone know what threads these barrels have, and if they're any good? Or, if necessary, an alternative?

9mm AR barrels with pinned FSB seem to be something of a rare bird.

1/2x36 I asked the same question in the industry forum and they responded. They kept the original 1/2x36 threads.

Cool. I figured it was one of the two. Thanks!