M7 SMG

"I’ve seen a Spartan use two at once, tearing the crap out of the little ones; sending the big ones down in bloody heaps. But I guess that’s what ya gotta be to pull it off: an action-movie hero or a seven-foot-tall walking tank."

- Anonymous E2-BAG/1/7 serviceman

The M7/Caseless Submachine Gun (SMG) is a personal defense weapon used by infantry, special forces, and vehicle crews of the UNSC Defense Force. A suppressed version of the weapon, the M7S Caseless Submachine Gun, is often issued to special operations personnel.

Design details
The M7/Caseless Submachine Gun is an automatic submachine gun that fires from a 60-round magazine which is placed horizontally on the left side of the weapon. Due to the odd horizontal placement of the magazine on the weapon, it can be assumed that the magazine utilizes a circular ramp where the magazine meets the breech. This rotates the horizontally stacked rounds in the magazine 90 degrees until they align with the horizontal breech. An example of this can be seen in the present day Fabrique Nationale P90 SMG.

The SMG has a polymer handle, folding fore-grip, iron sights, and collapsible buttstock, as well as a titanium body. The SMG must be cocked before it can fire the first round. The charging handle is located on the right side of the gun and does not move during operation. Once the first round is fired, the gases from previous rounds force the breech to rotate and chamber a new round. Once the magazine is empty, the handle although not illustrated in-game, can either be pulled back and locked or it can be fully cycled after a fresh magazine has been housed. If it is first pulled back and locked, then it must be pushed forward in order to chamber a new round. The magazine release button is located between the red dots on the receiver and needs to be pressed before it can be flicked off. There is no ejection port due to the nature of the rounds fired.

The SMG has a rifled barrel that is 15 cm (5.9 in.) long. This weapon can also be affixed with a suppressor; in this configuration, the weapon is designated the M7S Caseless Submachine Gun. The weapon is 47.4 cm (18.66 in.) long with the stock retracted. The stock is always retracted in-game and has a maximum length of 62.7 cm (24.68 in.) when the stock is fully extended.

Ammunition
Unlike most UNSC weapons, the M7 uses caseless 5x23mm ammunition, meaning it does not have a metallic casing surrounding the powder and sealing the bullet, propellant, and primer together. Instead of using this casing, the round uses a combustible adhesive to seal these components together. Because the adhesive and propellant are both vaporized when fired, there is no need to eject spent casings. Though not featured in-game, contemporary caseless ammunition is highly susceptible to cook-off, the accidental firing of rounds due to built-up heat in the receiver.

This feature is very beneficial. In addition to increasing fire rate by removing the extraction and ejection phases of the weapon's cycle, it reduces friction inside the magazine, one of the main causes of malfunctions in weapons. This is also conducive to dual-wielding, since the user need not concern themselves with hot brass expelled from the weapon held in the left hand. The projectile itself is jacketed in metal, usually a copper alloy in standard military ammunition, to aid in penetration of the target. Caseless rounds are actually embedded into the block of propellant, reducing their length, allowing more ammunition to be stored in a smaller space.

Despite the M7 typically firing caseless rounds, there is a variant of the weapon that can be loaded with more traditional cased ammunition.

Advantages
Since it has a larger magazine than the MA5C assault rifle, players will have to reload less often than if they were to use the MA5C. Because of the large magazine, one can easily continue through targets with little pause for reload. Like most UNSC firearms, the SMG is extremely deadly against unshielded targets, and can kill them rather quickly. In addition, the SMG serves as a better close range secondary weapon when already armed with a Battle Rifle. In combination with the battle rifle, the SMG makes a reliable close range support weapon when shotguns and swords are not available. The SMG serves better than the MA5C at close range due to its larger magazine and faster firing-rate, and is an excellent choice of replacement for the Assault Rifle in close combat situations, but not at medium range.

The SMG can also form part of the most effective dual-wield combos in the game. The SMG, when dual-wielded with a plasma rifle, can be a deadly combination because the plasma rifle depletes the opponents shields and the SMG's rounds do the rest. Another favored combo is dual-wielding the SMG with the plasma pistol. This tactic is often referred to as the "noob combo". The charged shot from the plasma pistol will deplete the shield of the opponent and a full burst of SMG fire will tear through the now-exposed flesh and armor. In Halo 3, the SMG has been improved. By itself, the SMG can be an extremely devastating weapon in close-quarters combat, simply because of its high ammo capacity and fast melee.

Disadvantages
The SMG has received the nickname "the Bullet-Hose" due to its high rate of fire, low accuracy, and inability to be fully controlled when fired in full-auto. The SMG's primary limiting factor is its poor accuracy, which limits its use to close range. At close ranges, the SMG is very powerful and is only outperformed by the shotgun, the energy sword, and the gravity hammer. Like most other human weapons, the SMG performs relatively poorly against shields, though this weakness is negated by wielding it in conjunction with a plasma rifle or plasma pistol. As stated before, the gun has recoil which causes the barrel to climb after continuous fire and will climb faster if players dual-wield it. This forces the players to continually move their reticule down to keep the enemy in their sights but is not a big limiting factor. This, as well as the poor accuracy can be slightly countered, using a burst-fire technique, unleashing about five bullets each pull of the trigger. It also has the problem of an extremely long reload time when dual-wielded, making it easy to be killed while changing magazines. This problem however can be solved by volley firing the weapons, so while one is reloading the other is still firing. This tactic reduces the power of having two SMGs but gives the advantage of approximately 40+ seconds of non-stop firing.

Changes from Halo 2 to Halo 3

 * Red dots at the receiver end of the magazine
 * Slightly shorter foregrip
 * Increased accuracy, range, damage and rate of fire
 * There is now a delay before the barrel actually starts to climb.
 * The sound of the weapon's firing is slightly different.
 * The handle is more curved and less rectangular.
 * The weapon's finish is a darker, matte black.
 * When dual-wielding SMGs, the weapons are held farther from the body.
 * The player's reserve ammunition capacity is reduced.

Influence
The M7 appears to share its design from several real-world firearms; the Heckler and Koch G11, a caseless prototype assault rifle developed in the 1980's, the Fabrique Nationale de Herstal P90 and the Heckler and Koch MP7. The M7 shares its caseless ammunition concept and feed mechanism from the G11, and its design from the latter two. As the MP7 and P90 are both personal defense weapons, it can be assumed that the M7 falls under this classification as well. Its slanted front, foregrip, collapsible stock, and possibly name come from the MP7, while its ergonomic grip and the horizontal magazine configuration come from the P90.

Campaign

 * The M7 SMG is always a devastating weapon when dual-wielded against Elites and Brutes.
 * Dual-wielding a M7 SMG with a plasma-based weaponry works extremely well against against shielded targets.
 * Short controlled bursts with a single SMG is required to maintain ammo and effective range when engaging Covenant forces.

Multiplayer

 * In Halo 2, the M7 is not a sound weapon to start with, but if no other option is available, minimize being killed by staying in a safe zone until a better weapon becomes available.
 * If stuck with an M7, stay in close quarters, and do not venture out where an opponent can take the player down with longer-ranged weapons.
 * Dual-wielding the M7 SMG with a plasma-based weapon such as the plasma rifle works very effectively against against shielded targets. Dual-wielding a M7 and a pistol can be tactically useful, as it can create a deadly combo that can take out targets quick and efficiently. However, it requires a great deal of skill and hand-eye coordination. The combination of a full-auto and a semi-auto weapon can be confusing and hard to handle when aiming at an opponent.
 * The M7 is a good choice as a suppression weapon, because of the sheer volume of fire being produced if dual-wielded, especially when engaging a nearby battle rifle or sniper rifle.

UNSC remarks

 * “The recoil isn’t bad but the M7 itself is relatively light. Not unpleasant to shoot, but a little tricky to control—it’s all about controlling the impulse.”
 * “It’s actually comparable in weight to the M6 — favorably, in fact. That and not having to worry about the hot casing dropping down on your boot makes it a pretty clear choice which one I think is the better system.”
 * “Yes; I have fired it one-handed with the stock collapsed and the foregrip folded. No; I was not driving at the time, I was shotgun. Did I hit anything? Don’t know—probably never will—no more bogeys afterward, though.”
 * “It’s not a death ray but nobody likes getting shot. Not even Bravo Kilos. And you can fill the air with a lot of lead with an M7."
 * “The M7 is the wave of the future. Hopefully the Romeo Echo Mike Foxtrots will finally realize the benefits of caseless ammunition.”
 * "I’ve seen a Spartan use two at once, tearing the crap out of the little ones; sending the big ones down in bloody heaps. But I guess that’s what ya gotta be to pull it off: an action-movie hero or a seven-foot-tall walking tank."

Trivia

 * In Halo 2, when the player wields a single M7, the SMG's the stock is extended. when the M7 is dual-wielded, the stock is collapsed. In Halo 3, the stock remains locked halfway in both the first-person and third-person animation, whether the weapon is being dual-wielded or not.
 * In Halo Wars and The Babysitter, the M7 SMGs used by Douglas-042, Alice-130, and Dutch eject shell casings, despite the M7 typically using caseless rounds. This is because they are using a model designed to fire cased ammunition.
 * The Halo Encyclopedia states that, among its flaws, the M7 is prone to malfunctioning. This seems unlikely, as the weapon fires caseless ammunition, meaning no case is ejected from the gun, which is where most weapons malfunction. However, the caseless ammunition itself may be the source of some malfunctions. If a round does not fire, it is very painstaking to remove because of the lack of an ejection port. Also, the ammunition is prone to accidental firings if the air around it gets too hot, such as in cases where the gun overheats. Other mechanical aspects, such as the circular ramp that loads in the rounds are a possible area for a malfunction, as double-feeding or a misfire could occur quite easily in a mechanism like that.