M6 series

"The M6 has been in service for about a hundred and forty years… it’s amazing to think how little it has changed in all that time."

- Anonymous UNSC serviceman

The M6 Personal Defense Weapon System is a series of short-barreled weapons produced by Misriah Armory.

Introduction
They have seen widespread distribution through the United Nations Space Command Defense Force as lighter firearms, although they are not always seen as primary weapons because of their lighter penetrating power. They have seen usage in the UNSC for almost 140 years.

Characteristics
The M6 series weapons are recoil-operated and magazine-fed, and typically fire 12.7 x 40mm projectile ammunition, and despite the large caliber, often times "exotic" ammunition is not utilized. They are also remarkably large and overpowered to an extent, appearing to be redolent of a cross between a pistol or a rifle in size. In addition to power, the M6 line of weaponry is designed to be rugged and reliable, and the guns are able to remain operational after Slipspace transitions and high-g aerial maneuvers. However, the heavy weight limits its distribution amongst personnel, and the M6 weapons have a tendency to drop casings on the wielder's foot, leading some UNSC personnel to favor the M7/Caseless Submachine Gun which operates on a caseless system.

They have remained remarkably unchanged during its decades of service, although there are a large number of variants, such as the A, B, C, D, G, and J variants. The M6 series handguns are issued in three different finishes: hard chrome, black polymer, and electroless nickel.

Known Models

 * M6A Handgun - Used mostly by Civilian Security Forces, standard issue/black polymer finish.
 * M6B Handgun - Used mostly by civilian security forces, KFA-2 x2 scope, hard chrome finish.
 * M6C Magnum Sidearm - Halo 2-era UNSC sidearm, 'up-sized', armed with High Penetration ammunition, black polymer finish.
 * M6C/SOCOM - Halo 3: ODST-era UNSC sidearm, issued with smart-linked 4X scope VnSLS/V 6E, sound suppressor, muzzle brake, and black polymer finish.
 * M6D Magnum Sidearm - Halo: Combat Evolved-era UNSC sidearm, 'up-sized', armed with High Explosive ammunition and featuring KFA-2 x2 scope.
 * M6E Handgun: standard issue/electroless nickel finish.
 * M6F Handgun: smart-linked scope KFA-2/electroless nickel finish.
 * M6G Magnum Sidearm - Halo 3/Halo: Reach-era UNSC sidearm, 'up-sized', armed with High Explosive ammunition and electroless nickel finish.
 * M6H Handgun: 'up-sized', smart-linked scope KFA-2/electroless nickel finish.
 * M6I Handgun: select-fire variant; detachable shoulder-stock/black polymer finish.
 * M6J Carbine - UNSC Army carbine variant of the M6 series. 355mm barrel, detachable shoulder-stock/electroless nickel finish.
 * M6K Handgun: police 'undercover' variant; 6 round magazine capacity/black polymer finish.

Differences between games
In Halo: Combat Evolved, the Magnum had a large magazine, did high damage, and fired fairly quickly. However, with the advent of dual-wielding in Halo 2, the Magnum was severely reduced in power. Its fire rate decreased by more than half, its magazine shrunk, and it did much less damage. This change carried over to Halo 3. Bungie's act of decreasing the Magnum's power generated a massive outcry from gamers, prompting them to revive the Halo: Combat Evolved version of the weapon. This is also canon, as this version of the M6 would logically have been in use at the Fall of Reach as well as the events at Installation 04, due to them taking place mere days apart.

Trivia

 * Common slang terms for the M6 series handguns include go-mag, hand cannon, and power drill.
 * Despite using the same kind of ammunition, the M6D and M6G cause different levels of damage in-game; this is due to game balancing
 * Some variants of the M6 series have been 'up-sized' to be used by SPARTAN-IIs. The 'up-sizing' factor is 117%, a reference to John-117.