T-Shirts & More!: Lena shows off the Sig Sauer MPX in the first video on YouTube to feature the platform in all its full auto glory!br Introducing the SIG MPX, a machine pistol that redefines the category. This video contains updated information on the SIG MPX Carbine version. It shows how to .br Suppressed SIG MPX 9mm submachine gun (SMG) and SIG MPX 9mm machine pistolSMG being fired on semi-auto and full-auto, respectively, at the SIG .br Our new Sig MPX submachine gun.