13.5 LH Thread Cleaning Tap

The threads on a stock MPX barrel have about 3 mm of thread and a taper for interfacing with Sig's proprietary taper mount system that is integral to the barrel. That way Sig firearms are most compatible with Sig muzzle devices, and vice versa. It's a shame, I'm having mine re-threaded. Thanks Sig.

Anyways, I couldn't wait to shoot it suppressed so I threw on my HK Parts 3-lug adapter which has almost an inch of exposed thread. There was a lot of thread left over in front of the muzzle. I kne