M6A magnum
From Halopedia, the Halo wiki
The M6A Handgun[1] is a United Nations Space Command firearm.
It 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.
The M6A Handgun is believed to fire 12.7mm x 40 projectiles, possibly semi-armor piercing (SAP). But the M6A might actually fire a smaller round as they are more comfortable to shoot.
The M6A was made around 140 years before 2552, being made in 2412.
