M6A magnum
From Halopedia, the Halo wiki
The M6A Handgun[1] is a United Nations Space Command firearm.
Background
The M6A is a variant of Misriah Armory's M6 Series of sidearms pistols, and is noted for its comfortableness and light weight. However, it sees only widespread distribution in civilian security forces such as Law enforcement and not mainstream UNSC military units. This model began production around 140 years before 2552.
The M6A Handgun is believed to fire 12.7mm x 40 projectiles, possibly semi-armor piercing (SAP).
