Halo Alpha
Halo Alpha

“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,[2] more simply known as the SMG, is a United Nations Space Command infantry and special operations weapon. A suppressed version of the M7/Caseless Submachine Gun, known simply as the M7S Submachine Gun, is also available for UNSC special operations.[3]

Design Details[]

The M7/Caseless Submachine Gun is a fully automatic UNSC 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 vertically 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, collapsible buttstock, iron sights, and a titanium body. Prior to firing when empty, the bolt must be cycled to chamber the first round. The charging handle is located on the right side of the gun and does not move when firing. 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 charging handle, although not illustrated in-game, can be either pulled back and locked or it can be fully cycled after a fresh magazine has been inserted. 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 left side of the receiver and needs to be pressed before the magazine can be released. There is no ejection port due to the nature of the caseless rounds fired. 

The SMG has a rifled barrel that is 15 centimetres (5.9 in) long.[2] The weapon is 47.4 centimetres (1 ft 6.7 in) long with the stock retracted.[2] The stock is always retracted in games and has a maximum length of 62.7 centimetres (2 ft 0.7 in) when the stock is fully extended.[2]

The SMG can also be affixed with a suppressor, flashlight, reflex sight, and smart-link scope. In this configuration, the weapon is designated as the M7S Submachine Gun.[3]


Main article: M443 Caseless Full Metal Jacket

The SMG uses 5x23mm caseless ammunition, a radically different kind of ammunition than the kind found in other UNSC weapons. This ammunition is classified as "caseless," meaning it does not have a metallic casing that holds together the bullet, propellant, and primer. 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 jamming 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. It also prolongs the life of the barrel since copper is more mallable than the barrel material, preventing wear on the rifling. Caseless rounds are actually embedded into the block of propellant, reducing their length, allowing more ammunition to be stored in a smaller space.

The SMG's 5x23mm (.197 caliber) rounds, while smaller than most other SMGs, could classify it as a PDW (Personal Defense Weapon), from which it has already taken several design forms.


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 firing 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 however 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 armor piercing rounds do the rest. Another favored combo is dual-wielding the SMG with the Plasma Pistol, often referred to as the "Noob Combo." The charged shot from the Plasma Pistol will deplete the shield of your opponent and a full burst of SMG fire to tear through the now-exposed 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, lightning-fast melee, and fast rate of fire.


The SMG has received the nickname "bullethose" 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, Energy Sword, and Gravity Hammer. Like most other Human weapons, the SMG performs relatively poorly against shields, though this weakness can be 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 reticle 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 firing is slightly different.
  • Handle is more curved, less rectangular.
  • Other various minor cosmetic changes.
  • Colour is a darker, matte black.
  • Magazine is the same colour as the weapon, not transparent.
  • When dual-wielding SMGs, the SMGs are held further away from the body.



  • The M7 SMG can be a devastating weapon when dual-wielded against Elites and Brutes.
  • Dual-wielding an M7 SMG with a plasma-based weaponry works extremely well against shielded targets.
  • Short controlled bursts with a single SMG is required to maintain ammo and effective range when engaging Covenant forces.
  • The M7 is highly effective in mowing down large groups of Grunts and Drones, and with Jackals it can take them down easily if you take the time to aim for the opening on the side of the shield.


  • The M7 in Halo 2 is not a sound tactical weapon to start off 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 shielded targets. Dual-wielding an M7 and an M6C/M6G might sound 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. The weapon's rate of fire can also be disorienting; when firing upon a Battle Rifle user or a Sniper Rifle user close by, it becomes hard for them to aim and gives you the advantage to charge, assuming you are close enough to your opponent.
  • The SMG is a solid CQB weapon (or a dual-wieldable, non-power weapon), apart from the Shotgun, Mauler or Energy Sword. It is also newbie-friendly, due to the fact that it has a large magazine capacity and is suitable for the "spray-and-pray" method. It will also give the player a chance for an easy kill, since its magazine will outlast many other weapons excluding the Spiker, Assault rifle and Machine Gun Turret in a one-on-one confrontation.

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.”


  • A submachine gun is a class of light, compact automatic firearms designed to fire handgun rounds. Strangely, the 5x23mm caseless ammunition is only unique to the M7; the M6 series of pistols fire a larger 12.7x40mm round. However, the weapon could most likely be based on the Heckler and Koch G11 assault rifle, which fires a 4.73×33mm caseless ammunition.
  • In Halo 2, when the player wields a single M7, the SMG's 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, the M7 SMGs used by Douglas-042 and Alice-130 eject shell casings, despite the fact that the M7 fires caseless rounds. In The Babysitter, the M7S is seen ejecting shell casings.
  • In Halo 2 and Halo 3, it is possible to hold one half more ammunition for the SMG and any dual-wieldable, ammo-based weapon. Simply pick up an SMG, switch to your other weapon, pick up some other dual-wieldable weapon, dual-wield it with an SMG, and then swap out the other weapon with another SMG, giving you three. You will be able to pick up a full ammo supply for all three weapons, giving you one half more than usual. This is very useful for ammo-poor areas and extended fights.
  • In Halo 2, the M7 replaces the MA5B Assault rifle from Halo: Combat Evolved. Both have the same magazine size, rate of fire, and reticle.
  • The audio file used to indicate receiving more ammunition for the M7 in Halo 2 and Halo 3, and ODST is used in Halo: Reach to indicate receiving ammunition from a resupply crate.
  • The ammunition type is listed on the side of the magazine and is visible from the third-person view.







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