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.
The M6 series has been in production for about 150 years.
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 "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 they 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 does not eject spent cartridges, due to the caseless design of its rounds.
The M6 series has remained remarkably unchanged during its decades of service and has been specialized into a number of variants A, B, C, D, E, F, G, H, I, J, K, and S. The M6 series handguns are issued in three different finishes: hard chrome, black polymer, and electroless nickel.
|N/A||M6A Handgun||Used mostly by civilian security forces, standard issue/black polymer finish.|
|N/A||M6B Handgun||Used mostly by civilian security forces, KFA-2 ×2 scope, hard chrome finish.|
|M6C Magnum Sidearm||Halo 2/Halo 2: Anniversary-era UNSC sidearm, up-sized, armed with High Penetration ammunition, black polymer finish.|
|M6D Magnum Sidearm||Halo: Combat Evolved/Halo: Combat Evolved Anniversary and Halo 5: Guardians-era UNSC sidearm, up-sized, armed with High Explosive ammunition and featuring KFA-2 ×2 scope.|
|N/A||M6E Handgun||Standard issue/electroless nickel finish.|
|N/A||M6F Handgun||Smart-linked scope KFA-2 ×2/electroless nickel finish.|
|M6G Magnum Sidearm||Halo 3 and Halo: Reach-era UNSC sidearm, up-sized, armed with High Explosive ammunition and electroless nickel finish.|
|M6H Handgun||Halo 4, Halo: Spartan Assault and Halo: Spartan Strike-era UNSC sidearm, up-sized, smart-linked scope KFA-2 ×2/electroless nickel finish.|
|N/A||M6I Handgun||Select-fire variant; detachable shoulder-stock/black polymer finish.|
|N/A||M6J Carbine||UNSC Army carbine variant of the M6 series. 355mm barrel, detachable shoulder-stock/electroless nickel finish.|
|N/A||M6K Handgun||Police undercover variant; 6 round magazine capacity/black polymer finish.|
- "The M6 is either the world's biggest pistol or the world's smallest rifle — I'm not sure which."
- "It's strange. Normally a big bore means access to a greater variety of exotic munitions, but we just don't see that variety in the field."
- "The M6 has been around forever; the number of variants and configurations is dizzying... have you ever seen an M6J(C) — the Army's carbine variant?"
- "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."
- "The longevity of the M6 has always been more about pork barrels and Slipspace travel than reliability or the so-called brilliance of its design."
- "The A's and B's are way more comfortable to shoot, but you don't see many of them outside of civilian security forces anymore."
- Common slang terms for the M6 series handguns include go-mag, hand cannon, and power drill.
- 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.