The modified P320 was subsequently designated the M17 (Full-Size) and M18 (Carry) for U.S. On January 19, 2017, the United States Army announced that the SIG Sauer P320 MHS variant had won the military's Modular Handgun System trials. Brown triggers, levers and catches were used only early in production. The XM17 prototype with 17-round magazine inserted. Įvery M17/M18 handgun is test fired before leaving the factory with 13 rounds - three to break in the weapon and ten to test accuracy. The Modular Handgun System has self-illuminating tritium sights for low-light conditions, an integrated rail for attaching enablers and an Army standard suppressor conversion kit for attaching an acoustic/flash suppressor.