M90 Close Assault Weapon System

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

- Unknown Marine

Description
The M90 Close Assault Weapon System (abbreviated M90 CAWS), more commonly known as the M90 Shotgun, is the United Nations Space Command's resident shotgun series. This weapon is also unofficially referred to as the "Shotty".

Introduction
The M90 Shotgun is the main UNSC close combat weapon, packing extreme killing power at close range. It can kill almost any enemy in one hit if every pellet makes contact, and can usually kill up to three Covenant Grunts with only one blast at a similar distance. It is often wielded in urban conditions, where the tight spaces are conducive to the shotgun's wide spray. The shotgun also makes a perfect defensive weapon to fend off Covenant boarding parties inside warships, and is particularly effective against the Flood due to the tendency of Flood forms to close in and melee their targets.

Not much has changed in the shotgun's design since its conception. The weapon's power lies in the great stopping power of its quad-ought, or 0000, ammunition load, which, while extremely powerful in close-quarters combat, is useless at anything but extremely short distances. (However, even though 0000 is specified, 16 individual pellets is not even single-ought. In fact, the Soellkraft Hippo round is pretty much buckshot, whereas quad-ought would be slug, or a single massive round!) If the M90 is the only weapon you possess, then you may need to run at enemies to take them down. This poses the threat of taking hits as you run, thus depleting your shields. However, it should be noted that the shotgun wielder can occasionally engage enemies at medium ranges, if circumstances allow. (especially in Halo:C.E. where it can take down a banshee low on shields half way across a map like Blood Gulch.) In the time space between Halo: Combat Evolved and Halo 3, three models were introduced as shown below.

M90 Mk I
The first model presented in the Halo series, introduced in Halo: Combat Evolved. It contained 12 shells at a time (the biggest shotgun ammo capacity in the Halo trilogy), and the player could carry up to 60 more shells (a total of 72 shells). It had the longest effective range of all three models, and could kill weak or injured 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 had the capabilities to take on lightly armored vehicles such as the Ghost effectively. In the original Halo, players could hold the trigger button down for continuous (not rapid) fire. If the player fires the entire magazine, the character model will rack the shotguns pump after reloading, although most players usually opted to reload after every shot. This version of the M90 shotgun had a quicker reload than the Mk.II model. The M90 Mk.I shotgun was the best anti-Flood weapon in Halo: Combat Evolved. Using it, players could engage multiple Flood targets at point blank, close, and even medium range, although each individual shots effectiveness varied greatly. However, this shotgun model was a guaranteed kill at close range, and players came to rely heavily on this weapon in the later stages of the first game.

M90 Mk II
The second model, the M90 Mk II, was used in Halo 2. It changed significantly from the Mk I. Its appearance slightly changed, most notably with the green Iron Sights instead of blue. Its performance changed as well. It could not kill targets at more than a few feet away, though a quick shot-melee combo would usually kill an enemy very quickly. The shotgun was only very effective at extremely close range, and the player only carried 36 spare shells (a total of 48 shells). Unlike the previous version, it had almost no stopping power when used against vehicles, and like before, with the range decrease, its effectiveness against the Flood was reduced slightly. It probably took this change as Bungie introduced the Energy Sword as a usable weapon, and wanted to "even the odds". It never cocked after reloading. It was also extremely effective against berserk Brutes.

M90A
The newest model, the M90A, is used in Halo 3. There are a variety of graphical and gameplay changes from the previous models, and it is arguably the most powerful variant of the trio. The blue iron-sights have been reintroduced, it has a longer barrel and a flashlight is mounted on the side. Unlike the older models which had a 12 shell magazine, it only has a 6 shell magazine. The player can carry 30 spare shells or 5 Magazines (a total of 36 shells or 6 Magazines), as opposed to Halo: Combat Evolved's 72. To make up for this, its effective range is far greater than the M90 Mk II, as it can kill targets at two or even three times the range, depending on their health. It even has enough firepower to send a Warthog out of control if the vehicle is shot in the right place. This variant of the Shotgun also appears bulkier and stronger than its Halo Combat Evolved and Halo 2 relatives. It is always cocked after reloading.

Similarities/Differences Between The M90 Models

 * The Shotgun appeared in Halo: Combat Evolved in the levels 343 Guilty Spark, The Library, Two Betrayals, Keyes and The Maw. The weapon's model was the Mk I, and had very pronounced blue front and back sights. It may have fired a different kind of ammunition than its Halo 2 counterpart, as the range of this model was much longer, and the damage was slightly higher. The M90 Mk I was pump action (as every other shotgun model), but the player could hold the fire button for continuous fire and pump (This cannot be done in Halo 2 and Halo 3). The player could carry a very large amount of shotgun shells at one time, a total of 72 shells (with a rare overload of slightly over 100).
 * It also appeared in Halo 2. This model was the Mk II, and although it did more or less the same amount of damage, its range was greatly reduced. It also featured a green iron sight and a decreased ammo capacity, with the player only able to carry a total of 48 shells at a time. It should also be noted that the reload time was significantly slower.
 * The newest model, the M90A appears in Halo 3, as it did in the Beta. The original blue iron sights have returned, and it now has a longer range, but half the magazine capacity of the Halo and Halo 2 models. The player can carry up to a total of 36 shells.
 * The DTM Series is available in 20 gauge, and 10 gauge for the civilian market. The 8 gauge is only sold to law enforcement (such as the WST DTM/LE model) and military agencies.
 * The M90 series of shotguns have another feature as well: all have a detachable stock, allowing the shotgun to be used at even closer quarters. If you look carefully at the M90 (any game), you can see that the stock is held onto the actual firearm by a "pin and button" system.

Advantages
Since the Shotgun fires 15 spreading pellets per close-range shot, the combined relative force of each relatively weak pellet does a significant amount of damage. Its high damage potential (as much as a rocket in Halo: Combat Evolved at close range) makes it effective against almost any Covenant unit (even the Hunter, if shot in its exposed back), but only if the player can get close enough to render the gun effective. In addition, this weapon is extremely effective against all forms of Flood at short and medium ranges (depending on the model), and is capable of eliminating Combat Forms in one shot, and a group of Infection Forms with one shot also. The shotgun also reloads in a different manner than the rest of the weapons in Halo. Each round is put into the shotgun, one-by-one, so reloading all six/twelve shells at one time may take a while. However, the player may interrupt the reloading process at any time and fire with however as many rounds are currently loaded into the weapon. Another popular way of firing the shotgun involves inserting a shell, firing, and then inserting another shell, etc. While this takes slightly longer, it has the advantage of always having shells chambered. Apart from that it is devastating in close combat, stronger than an Energy Sword swipe, but slightly weaker than the Energy Sword lunge, although this is the weapon to use against the Energy Sword in close combat. The only counter weapons at close range are the Energy Sword, and the Sniper Rifle. Probably one of the most effective ways to fight is to fire one shell at very close range and immediately after that, melee. You can do this by basically pressing both the right trigger and the B button at the same time with only a slight pause between pressing the buttons. The shell will usually take out your opponent's shield leaving him with basically no health and the melee will most likely kill him. In addition, it is very effective to wait around corners with this weapon to kill anyone that comes around. This is an easy way to get a killing spree and shotgun spree.

Disadvantages
While highly effective at close range, at longer ranges it is rendered useless. The shotgun's shots spray very quickly, thus at farther ranges when you fire the shotgun, only 1 or 2 pellets out of the 15 might hit. Also, the time needed to reload can make fighting at long range even more difficult, especially without cover to hide behind. As compensation for this fault, a medium or long range weapon like the Battle Rifle or the Halo: Combat Evolved M6D Pistol will make up for the Shotgun's medium to long range damage problem. And reloading can be fixed by being able to fire a shot at any time while the gun is reloading.

In addition to this, the melee for the shotgun is considered to be powerful, but tends to be somewhat inaccurate, especially against smaller enemies, however it works very well on the Flood, as it is often powerful enough to break combat forms, rendering them incapable of being resurrected.

Campaign Recommendations
One of the most dominating weapons in the Halo Trilogy, the Shotgun shows its most effective side in The Library in Halo 1 and 2 and in Sacred Icon in Halo 2. Despite its very slow reload rate, this is arguably the best weapon against the Flood. Players might want to duck behind somewhere just in case you need to reload. This weapon is easily the best choice in the game for taking out powerful enemies such as groups of Flood Combat Forms, Elites, and Brutes. Even on Halo: Combat Evolved Heroic difficulty, it is possible to take out Elites with as few as two shells, and only on Legendary do the Flood become capable of surviving a direct hit from the shotgun.

In Halo 2, Brutes, Councilor and Ultra Elites are the only ones that can survive a point blank shotgun blast on Normal difficulty. (Hunters can be killed by shooting directly into the orange fleshy openings on their armor.) However, on Legendary difficulty anything higher than a Minor Elites shielding and health can withstand a point blank shotgun blast (this includes Hunters). Beware for in Halo 2 Brutes also wield shotguns.

Multiplayer Recommendations
The shotgun's effectiveness in multiplayer games varies depending on the terrain; indoors and in tight spaces, the shotgun is unbeatable, and some consider it superior, to the Energy Sword. Many players carry the shotgun and a weapon that is very effective at medium and above ranges such as the Sniper Rifle, Covenant Carbine, M6D, or BR55 Battle Rifle, thus making for a more flexible arsenal. Continuous firing by using the magazine and loading one shell then firing does not affect the rate of fire significantly, prompting a few players to employ a tactic dubbed "shotgun sniping" as suppressive fire across medium-sized maps. On the Internet, many games are shotguns only, with most of these battles being set in the map Battle Creek. There is a move combo players commonly use with the shotgun: since the enemy players commonly are on the move when being advanced on by a foe with a "special" weapon like the Sword, Rocket Launcher, Shotgun or a vehicle, players with the Shotgun can finish enemies off safely and quickly by shooting them at a decently close range, then striking them with a melee attack immediately afterwords, guaranteeing an instant kill. This is often known as the Benton One-Two. This is most effective in Halo 3 due to the more powerful nature of both the shotgun and melee attacks. Also, if a enemy pops right up in your face, the natural way is to get close (probably close enough to touch them) and fire a shell. Which, (usually) will end in a instant kill. Also, most players don't notice a shotgun in enemy hands, and will try to melee you, despite your shotgun, as if they don't notice it. When they get close, they've sealed their death. If you encounter someone who snipes you since they know you have the shotgun, get a long range weapon quickly. Shotguns are useless at long range. The shotgun is also the only weapon to be used in the slayer variant Tower of Power. Best to carry a Battle Rifle with you, or some other medium to long range weapon. If not have a team mate with you who will have one.

Multiplayer Medals (Halo 3)

 * Shotgun Spree Medal - Gun down 5 opponents in a row with a shotgun without dying.
 * Open Season Medal - Gun down 10 opponents in a row with a shotgun without dying.

NOTE: You can only get the Shotgun Spree and Open Season medals if all your kills with the Shotgun are done by the blast itself, not by the follow-up melee or any other means that your opponent was finished.

Ammo
The M90 Shotgun uses the Soellkraft 8 Gauge magnum shotgun Shell. This is an incredibly large round, not used by most modern militaries, but recoil has been said to be relatively low, so either technology must have improved in the future, or the one wielding it (Master Chief, the Arbiter, Brutes, etc.) is strong enough to handle it compared to most others. The shells have a hippo on the side in Halo: Combat Evolved. The shotgun in Halo 3 has only 6 shells per magazine, a downsize from Halo 2's 12. Yet it seems to be more accurate, and it can do minor/medium damage at medium range.

Influence
The mechanical design of the M90 shotgun is loosely based on the South African Neostead shotgun which features dual six-round top-loaded magazines. The weapon features two integral tube magazines with a total capacity of twelve rounds (6+6+1) and ambidextrous bottom ejecting shells. It is chambered for standard 12-Gauge 2.75-inch cartridges. The aesthetic design is a composite of multiple pump-action designs, most notably, the Mossberg 500.

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."
 * “I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."
 * “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 balance system of organs and the Flood don’t have that delicately balanced system of organs—it’s like shooting a motherf**king 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?”
 * "In a open area, with lots of space, you might as well carry a pea shooter."

Tips

 * The Shotgun is one of the best close-range weapons in the Halo Series. It is also best use against the Flood (or any other enemy for that matter).
 * A point-blank shot, followed up by a melee attack generally ensure a kill if your opponent survives the original blast.
 * To make sure you get an easy kill, crouch down and hide around corners and wait for an enemy to come, this technique can be reffered to as camping.
 * You can easily kill brutes by firing close up then meleeing or vice-versa.
 * The Melee attack from the Shotgun usually ensures that an active Flood combat form will be destroyed, rendering it incapable of being ressusitated by an infection form.
 * The shotgun has a slight delay after every round you fire.

Character Compatibility

 * Spartans
 * Marines
 * Elites (Halo 2 and Halo 3)
 * Brutes (Halo 2)
 * Flood Combat Form

Trivia

 * While an extremely powerful weapon in Halo CE and Halo 2 (capable of draining even an Elite Councilor's shield with one blow), it is much weaker in Halo 3: in fact, not only the pellets spread after a few feet, but it takes 2 shots from point-blank range to kill even a Brute Minor.
 * If you blast a hole with a shotgun in Halo 3 into the wall/floor, after around 6 seconds, the wall/floor will begin to regenerate.
 * Brutes are capable of holding a Shotgun with one hand, probably wielding it in the first place because of its sheer stopping power at close range.
 * In Halo 3, if you look at the Shotgun shell you can see the words Hippo EG-X on the front of the shell.
 * A player can make instant kills within close proximity by firing one round of a shotgun and the quickly pressing the B button to melee the vulnerable opponent. It is especially effective when used in conjunction with a Power Drain or a Bubble Shield.
 * In Halo: Combat Evolved and Halo 2, it is said to be a magazine fed weapon, which has caused much speculation as to whether there was a typo. This confusion is a common misconception, however, since Shotguns have an internal, non-detachable magazine which is different than the common assault weapon or sidearms magazine.
 * With good aim and a quick trigger finger, someone with a shotgun can kill the driver of a Mongoose or a Warthog.
 * In Halo: Combat Evolved you can hold the trigger to create an "automatic" fire mode.
 * In Halo 3 Matchmaking there is a gametype called Shotty Snipers where one starts with a Shotgun and a Sniper Rifle. There is also another gametype called "ShWATguns" in Matchmaking where one starts with only a Shotgun and has no shields.
 * The Shotgun is the favorite weapon of the Red vs Blue character, Sarge. This is apparently because he believes a soldier should always face his enemy in battle.
 * The M90 Mk. II has the shortest range of any shotgun in the Halo trilogy.
 * The Shotgun, next to the Energy Sword and Gravity Hammer is very useful for killing any known Flood form, even the Tank Form if you shoot it in the right spot.
 * The Shotgun is the weapon that can easily give you a Bulltrue if you have the right reflexes.
 * The Flamethrower and the Shotgun have the same blast radius for Halo: PC.
 * The Shotgun is the only weapon that doesn't have to be fully reloaded in order to fire because the shells are individually inserted into its tube magazine.
 * In Halo: the Flood it is stated that the M90 fires a twelve gauge shell, whereas in the Halo game manuals it states that the M90 fires an eight gauge shell.
 * Master Chief is seen wielding a Shotgun on the front of the Halo 3 instruction manual of the regular edition.
 * In Halo: CE, if you fire a round and swap it with a weapon on the ground before you pump it, it will pump itself a second after it hits the ground.
 * In Halo: CE on the map Sidewinder, there is a glitch that if you crouch on the ground and point a shotgun down at the ground and keep firing, shortly a purple ring will start to form around the black hole made by the shells, and the more you shoot the darker the purple ring gets (you must make sure you are out in the sun or it will not work.)
 * In Halo 3, the Shotgun is powerful enough to kill a Wraith in three shots if shot in the power core at the back.
 * The Halo 3 version is the only model so far to not feature a light on the bottom pump of the gun. Instead, it is located on the left side of the gun's barrel.
 * A shotgun is slightly more powerful than a Mauler. At point-blank range, a single shotgun round will kill an enemy, but from a mauler it will only lower the opponent's shields. However, dual-wielded Maulers are stronger and more effective in close combat situation than a Shotgun, though to melee someone you have to drop a mauler.
 * The shotguns in the Halo universe are actually inferior to some real shotguns we have now. For example, today we have 10 gauge semi-automatic and even fully automatic shotguns that have much less recoil than the ones in the Halo games,however the shotguns in Halo are eight gauge and thus have more damage.
 * The shotgun does the least amount of damage in Halo 3 and has the longest range in Halo CE. It does the most damage in Halo: Combat Evolved.
 * The shotgun is held different in every game.
 * The Shotgun spawn that had been originally placed on Narrows was replaced by the Rocket Launcher, whose spawn had been replaced by the Bubble Shield.
 * The Shotgun in Halo 3 has half the amount of ammo as it does in Halo: CE (It can only hold 30 extra shells, but in Halo CE it can hold 60 extra. The M90A Mk III can carry a maximum total of 36, while in Halo CE it can carry a maximum of 72).
 * When reloading your shotgun, a minor glitch that can occur is that your weapon discharges at random during the process. This can be a minor inconvinience in standard Slayer games, where Shotgun ammo is generally limited; but not in games like Shotty Snipers and ShWATguns, where ammo is infinite.