M90 shotgun

"I believe that the sound of racking the pump of a shotgun is universally recognized as "kiss your ass goodbye"."

- Anonymous E2-BAG/1/7 serviceman

The M90 Close Assault Weapon System is a pump-action shotgun used by the United Nations Space Command. Part of Weapon System Technologies' DTM Series, the M90 is a copy of Misriah Armory's M45 Tactical Shotgun.

Design details
The M90 CAWS is functionally identical to the M45E on which it is based. It is chambered for 8 gauge ammunition, typically the Soellkraft 8 gauge magnum in lieu of the M296 Magnum used by the M45. The cartridge provides immense firepower and ease of use while reducing the chance of puncturing spacecraft hulls. The weapon features a dual-tubular, non-detachable magazine that can be fed up to twelve shells through a top-mounted elevator. As the M90 is pump-action, spent shells are ejected each time the user works the action.

A tactical flashlight is mounted in line with the action shortly behind the muzzle. The iron sights may be colored faint blue (like the M45E's) or vibrant green. The weapon has an adjustable stock.

M90A variant
The M90A variant is similar in performance to the original M45, whereas the basic M90 is patterned after the M45E. The M90A has a magazine capacity of six shells rather than twelve, though this is compensated for by a longer barrel. The tactical light is mounted on the left of the action's grip instead of in front. The iron sights are colored blue.

Operational history
Shotguns saw prominent use during the frequent close-quarters urban combat of the Insurrection. Misriah Armory's M45 Tactical Shotgun (particularly the M45E variant) was acclaimed by its users, prompting Weapon System Technologies to develop a more economical and practical version. The resulting M90 Close Assault Weapon System is part of WST’s DTM Series, which is also marketed to civilians and law enforcement agencies. Over the next several decades the M90 eclipsed the M45 in both the military and the private sector, seeing widespread use during the Human-Covenant War. However, both models continue to serve alongside one another, particularly in the UNSC Marine Corps.

The M90 has earned a plethora of nicknames over the course of its service life, including "waste 'em", "deck clearer", "The Hammer", " Mop", "Broom", "Universal Translator", "High Stick", "Thunderer", "Betsy", "Equalizer", and "Okay-47".

UNSC remarks

 * “The kick is milder with the As — not that it was that bad to begin with — sometimes progress just seems like change, if you catch my meaning.”
 * “The adjustable stock on the M90 works just fine, but I’ve got a soft spot in my heart for the DTM/LE model — old habits die hard, I guess."
 * “Actually, I think the jury is still out on whether it means ‘STFU and STFD’ or ‘you ain’t gonna make it.”
 * “The action I saw against the Flood on Delta Halo was pretty limited — thankfully — and you would think that the M90 would be the ultimate anti-Flood weapon, right? Except that a shotgun is effective because it delivers a massive shock to a delicately balanced system of organs and the Flood don’t have that delicately balanced system of organs — it’s like shooting a mike foxtrot tree! All you can really hope to do is disassemble them as rapidly as possible in the correct order.”
 * “The shotgun is a specialist weapon — it has its uses, but they are limited. Maybe it is more accurate to call it a tool, as opposed to a weapon?”

Trivia

 * In Halo: Combat Evolved, the M90 shotgun shares its reticule with the sniper rifle and the PC-exclusive flamethrower.
 * In the second issue of Halo: Fall of Reach - Boot Camp, the captain of the retrieves several shotguns from a cryo chamber. In the first two panels, the shotguns appear to be M45s, though they resemble M90s in subsequent panels.
 * In Halo 2: Anniversary, if the player uses Active Camouflage while the M90 is equipped, the shells will be the only objects still visible. This could be because the shells are technically not attached to the shotgun (like the clips in other weapons) but rather held inside the weapon until ignited and fired. This is best seen when playing as the Arbiter.
 * Brutes on Delta Halo captured and used these shotguns during the Great Schism, along with other human weapons.

List of appearances

 * Halo: The Fall of Reach
 * Halo: Combat Evolved
 * Halo: The Flood
 * Halo: First Strike
 * Halo 2
 * Halo Graphic Novel
 * Breaking Quarantine
 * Halo 3
 * Halo Wars
 * Halo 3: ODST
 * Sadie's Story
 * Halo Legends
 * Homecoming
 * Origins
 * The Package
 * Halo: Blood Line
 * Halo: Fall of Reach
 * Boot Camp
 * Halo 2 Anniversary