M6 handgun

The M6 pistol, formally called the Pistol, Caliber .45, M6, is a semi-automatic handgun issued to UNSC personnel as a standard sidearm. The M6 comes paired with a KFA-2 2x smart-link module (SLM) that is capable of interfacing with a soldier's helmet to project a graphical gunsight on their Heads-Up Display, allowing for rapid target acquisition at close range, as well as providing a "zoom" capability which increases effective accuracy at middle range.

Overview
The M6 is a striker-fired, locked breech handgun that fires 15 rounds of .45 Parabellum ammunition from a double-stack box magazine. Various models of this weapon have been used by the UNSC Armed Forces for approximately 140 years.