As far as I know, only threaded barrels made by Glock have the 1 in 9.843" fast twist needed to stabilize the heavy projectiles used in subsonic ammunition.
Also, with a Glock factory threaded barrel you get the same polygonal rifling as the original barrel.
I have a Glock 9MM G19 barrel in M13.5x1LH, but they also make a G17, and a .45 G21 in M16x1LH.
Palmetto State Armory sells them.
AAC has Ti-RANT pistons in these thread pitches.