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 manufactured by Weapon System Technologies as part of its DTM Series. The M90 shotgun is commonly used by sportsmen, law enforcement, and United Nations Space Command's infantry and its special forces division.

Design details
The M90 shotgun features a dual tubular, non-detachable magazine, and is chambered for 8 Gauge ammunition. This provides immense firepower, ease of use and reduced capacity for puncturing the hulls of spacecraft. It is often employed in urban environments where the tight spaces are conducive to the shotgun's wide spray for defensive purposes and CQB combat.

The military-issued DTM series comes standard with an adjustable stock and pistol grip, although there are different models like the WST DTM/LE model which has a solid stock and no pistol grip. The DTM series of shotguns are available in 20 Gauge and 10 Gauge for the civilian market; the 8 Gauge is only sold to law enforcement and military agencies.

Ammunition
The M90 Shotgun is chambered for the Soellkraft 8 Gauge Shell, an incredibly large round not used by any 21st century military. Despite the size of the shell, the recoil has been said to be relatively low.

Advantages
The M90 Shotgun fires 15 spreading pellets per shot. The combined force of each relatively weak pellet does a significant amount of damage against almost any type of infantry, and the wide spread of the pellets in certain situations can inflict shrapnel damage to multiple infantry. The M90 shotgun's powerful 8 gauge round can punch through armor and Energy Shields easily, making the M90 a great weapon for taking on heavily armored infantry, and lightly armored vehicles. The M90's top loading system allows a user to reload the shotgun with speed and ease for quick firing.

Disadvantages
While highly effective at close range, the M90, like all shotguns firing buckshot, is rendered useless at long range, and should therefore be used in conjunction with a medium or long range weapon. The shotgun's pattern is extremely loose, and fans out quickly; thus, at farther ranges, only one or two pellets out of the 15 might hit. The M90, being a pump-action shotgun, must be cycled after every shot before it can be fired again; the M90 must also be reloaded shell by shell and does not use any type of external magazine. This can make reloading time-consuming when in combat situations, but it is useful to be able to "slam-fire"; the ability of the user to interrupt the reloading and shoot after you load a round. In close-quarter situations, the wide spread of the shell can potentially harm friendly infantry if the shotgun is fired at both the enemy and friendly troops. In real life, the ejection port being on top is itself a disadvantage, as the inside is partially exposed, meaning it is vulnerable to rain, dirt, and other elements. This will allow the magazine tube to become damp and/or dirty, and can cause malfunctions and stoppage.

Halo: Combat Evolved
The M90's incarnation in Halo: Combat Evolved is arguably the strongest version. It can hold 12 rounds, and the player can carry up to 60 more rounds for a total of 72 rounds. It has the longest and most realistic effective range of all the three models, and its fifteen tungsten pellets could kill, weaken or injure targets at short to medium ranges. Although it is more likely to kill a closer ranged enemy as the shotgun is weak on further distanced enemies, the shotgun could also kill nearly any infantry target at point blank range. It even has the capabilities to take on lightly armored vehicles, such as the Ghost effectively. Players could hold the trigger button down for continuous fire. To melee, the player swings the shotgun up and brings the butt of the weapon on someone's head/front. If the player fires the entire magazine or if the player picks up a Shotgun without a full magazine and fires it empty, the character model will cycle the shotgun's slide after reloading, although most players usually opted to reload after every shot. It reloads more quickly than in Halo 2.

Halo 2
In Halo 2, the M90 changed significantly from its predecessor. The only aesthetic difference is that the iron sights are green instead of blue, and the overall length of the barrel is shorter. The melee attack is much faster than in the original game, and the weapon is slung horizontally instead. Its performance is also drastically different as it can not kill targets at more than a few feet away, though a quick shoot-melee combo (the infamous "shotgun bang-whack") would usually kill an enemy very quickly. The player can only carry 36 spare rounds for a total of 48 rounds. Unlike the previous version, it has little power when used against vehicles, and like before, with the range decreased, its effectiveness against the Flood was reduced slightly. The weapon's action does not cycle after reloading, unlike the previous iteration of the M90.

Halo 3 and Halo 3: ODST
The M90A is used in Halo 3 and Halo 3: ODST. There are a variety of graphical and gameplay changes from the previous models. The blue iron-sights have been reintroduced, it has a longer barrel and the flashlight is now mounted on the side. Unlike the older models which had a 12-round magazine, the M90A only has a 6-round magazine. The player can carry 30 spare rounds for a total of 36 rounds. To make up for this, its effective range is far greater than that of the Halo 2 incarnation, as it can kill targets at two or even three times the range, depending on their health. The slide is always cycled after reloading, despite the fact that this would eject a round if one were already chambered. Like in Halo: Combat Evolved, the M90A is once again a powerful weapon for use against the Flood because of its increase in range and power, though the M90A may still require a player to shoot and melee a Flood target, depending on the type.

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

 * Slang names for the M90 include "waste 'em", "deck clearer", "The Hammer", " Mop", "Broom", "Universal Translator", "High Stick", "Thunderer", "Betsy", "Equalizer", and "The Okay-47".
 * In Halo: Combat Evolved, the M90 Shotgun shares the same reticule with the M7057/Defoliant Projector and the Sniper Rifle System 99C-Series 2 Anti-Matériel.
 * Halo: The Flood erroneously states that the M90 utilizes twelve-gauge cartridges.
 * 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.
 * The M90A's flashlight is only seen in use in Halo 3: ODST ' s campaign level Data Hive by an unidentified NMPD officer.
 * In Halo 2: Anniversary, if you use Active Camouflage while the M90 is equipped, the shotgun 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