This MPX has been converted from a standard 8″ barreled version, with ADCO Firearms LLC doing the barrel cut/threading/re-crown. The barrel has been re-threaded to 1/2×28 TPI, fitted with a HK Parts 3-Lug Adaptor, and includes the SB Tactical 3-Position Arm Brace. It is in like-new condition.
Unconventional design, unmatched performance, and familiar AR handling. The SIG MPX redefines the submachine gun category with a new level of operator safety, in-field adaptability and proven reliability in the harshest environments. Completely ambidextrous, the SIG MPX is great for left- or right-handed shooters with its dual-sided selector switch, magazine release, charging handle and bolt release. The SIG MPX operates from a fully-closed and locked rotating bolt, offering enhanced reliability and safety in use. A short-stroke gas piston allows the SIG MPX to run all weights and brands of 9mm ammunition with no adjustments to the gas valve. A full-length picatinny rail allows for solid, consistent mounting of optics and targeting lasers. The MPX K PSB features a 4.5″ barrel, telescoping 3-position brace and a short aluminum KeyMod handguard with handstop.