The MPX Copperhead features a monolithic Elite Series Cerakote® finish upper receiver, with an integrated stock knuckle lower, and a 3.5” barrel with integrated muzzle brake.

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.


  • Mag Type: MPX
  • Barrel Length: 3.5 in (89 mm)
  • Caliber: 9mm Luger
  • Height: 8 in [203 mm]
  • Overall Length: 14.5 in [368 mm]
  • Overall Width: 2.4 in [61 mm]
  • Twist Rate: 1:10
  • Weight: 4.5 lb (2 kg)
  •  Operating System: Gas Piston