The M56 Smartgun was a man-portable heavy machine gun with automatic targeting capabilities chambered for 10×28mm Caseless ammunition. It was notably employed by the United States Colonial Marine Corps. The M56A2[2][3] model in particular saw regular use in engagements with the Xenomorph and Yautja species.[2]


The M56 Smartgun system consists of four major components — the M56 combat harness, the Head Mounted Sight (HMS), the stabilized articulation arm and the gun itself.[4]

The M56 is carried into combat on a self-aiming stabilized mount that is linked to an infrared target tracking system for accurate, autonomous aiming.[2] The mount also negates the traditional need to position or set up the machine gun prior to opening fire. The gun itself is constructed largely from molded carbon fibre and light alloy stampings, though some interior parts are made of high-strength plastics.[5] The weapon's barrel is easily replaceable, able to be fitted with a dual bayonet; as seen with the M56 used by Sgt Drake, and air-cooled, although an additional heat sink attachment can be jacketed onto it to further improve sustained fire capabilities.[1] The M56 is 122 cm long, incorporating a 54.5 cm barrel, while the entire gun assembly, including the harness and a full load of ammunition, masses 17.82 kg.[5]

M56 Smart Gun diagram

A diagram of the M56 Smartgun.

Unusually, the M56 incorporates two different firing mechanisms in its design — firing is controlled either by depressing a red "fire" button mounted on the forward hand grip, or by lifting a firing handle mounted beneath the rear grip.[6] A selector on the forward grip switches the weapon between its Safe, Burst and Autofire settings. The Burst setting will fire four-round bursts, while the Autofire setting will continue to fire the weapon at its full cyclic rate so long as either of the triggers remains depressed.[6] Clicking off the safety will also automatically charge the weapon (provided there is not already a round chambered), although Marines have expressed disdain for this system, citing it as a major cause of stoppages, and prefer instead to manually charge the weapon after reloading using the cocking handle on the right side.[6]

The gun's rotating breech and feed mechanism are powered by an internal motor. In the event of a stoppage, the charging handle can be used to clear the mechanism.[6] Smartgun ammunition is stored on a roll of continuous plastic non-disintegrating link belt; the drum magazine on the M56 typically holds 500 rounds[1] and can be quickly reloaded in the field.

While the operator is standing, the gun is held and steered by its fore and back grips. Owing to the attachment point for the weapon's mount, it cannot be fired while lying prone; instead, the operator must employ a supine position (i.e. lying on their back). When supine, the gun is controlled with the foregrip and the charging handle, the latter of which must be locked forwards for this purpose.[7]

Operator's harness and mount[]

See also: M56 combat harness
M56 combat harness

The M56 combat harness.

The M56 is mounted on the M56 combat harness and is slaved to an advanced infrared tracking system, similar to that found in the USCM's UA 571-C Automated Sentry Gun. The chest piece contains the gun's tracking and targeting processor.[4] The processor is accessed from behind the chest plate, and can be easily replaced in the field should the unit fail.[4]

The M56 is securely attached to the operator by a stabilized articulation arm, attached to the left hip of the harness and connected via a coaxial cable the to processors and power outlets on the chest plate. The system's Head Mounted Sight is also connected to the tracking and communications systems in the chest plate. Power for the entire system is supplied by a standard DV9 lithium battery, plugged into the power leads that run from the articulation arm to the gun; removing this unit completely deactivates the weapon, rendering it useless.[8] Common practice in the field is to let the battery hang free beneath the gun where it can be easily accessed in an emergency.[4]

Smart Gun arm

The Smartgun's arm and battery.

The gun itself is self-steering on its mount, although firing must be triggered manually.[5] The articulation arm is gyrostabilized and provides additional recoil dampening, and is also capable of keeping the gun steady while the operator is walking or running.[7] When tracking a target, the arm steers the gun so as to aim the barrel at the target's center of mass. Working fluidly with this automatic tracking takes some training to master; the operator must be sensitive to the gun's movements and allow it to aim itself, although the weapon's motion can be overridden at any time by simply steering the barrel elsewhere.[7] Despite the gun's automation, Smartgunners require a combination of strength, mental ability and reflexes to master their weapon.[9]

Tracking systems[]

Vasquez and Drake with sights

Private First Classes Jenette Vasquez and Mark Drake with their sights.

When powered up, the gun begins tracking targets via the infrared detector mounted directly above the barrel. This scanner consists of a 256×256 element platinum-silicide focal plane array, cooled to 77 K (-196.15°C) by a tiny cryogenic gas cooler.[10] The system monitors a 30° cone in front of the gun. The tracking system also transmits thermal images to a miniature video display in the operator's eyepiece. If a target is detected, the tracker will overlay a lighted box or rectangle over the target's center mass on this display, highlighting it for the operator's attention. At the same time, the articulator arm will steer the gun towards the target, and once it has acquired a lock the operator will be informed by a target lock circle that illuminates on the display screen.[10]

In the event that the operator wishes to engage an opponent other than the one currently locked on to, they can simply steer the gun manually towards their preferred target and the system will acquire a fresh lock.[10] This tactic is also vital when faced with the use of infrared false-target decoys.


M250 High Explosive Armor Piercing (HEAP) round: The M56 Smartgun is chambered for the M250 10×28mm High Explosive Armor Piercing caseless round, a 230 grain, explosive-tipped projectile encased in a rectangular block of Nitramine 50.[6]

M280 High Impact (HI) round: The M56 Smartgun can also be chambered with 10x28mm High Impact rounds, which are both explosive and incendiary.[11]

Gun Team[]

As per USCM doctrine, Marines are organized into rifle squads at the lowest levels of organization. One element of this squad is the Gun Team. The Gun Team is made up of a rifleman with a M41A Pulse Rifle and a machine-gunner carrying the M56 Smartgun. The rifleman provides spotting and defense support for the machine-gunner, who in turn provides fire support for the rest of the rifle squad.


L56A3 Smartgun[]

The L56A3 Smartgun is a late-model variant of the standard USCM M56, which uses metamaterials instead of standard metals to reduce its mass and increase the operator's mobilities in the field. It was issued to the marines at the USS Endeavor. Its ammunition drum was reduced from 500 to 200 rounds and features the same auto-targeting system of the earlier M56 models, but with added modularity as the user can customize muzzle, barrel and weapon armature.

M56 Automated Combat Tripod (M56 ACT)[]


A M56 ACT deployed.

The M56 ACT was developed as a potential substitute for the UA 571-C, transforming the M56 into an automated turret. Even if proved to be less accurate than the standard UA 571-C it was reusable and faster to deploy, for that the M56 ACT was really appreciated by the USCMC.[11]

M57 Smartgun[]

The M57 is the 'sequel' to the M56 smartgun used for the better part of the last two decades. Unlike the M56, the M57's gun barrel does not autonomously track targets; instead the gun coordinates multiple guided projectiles. This increases fire rate significantly, reduces operator combat fatigue, and sidesteps lengthy training requirements. It also means that an M57 round can dynamically retarget mid-flight, should the firing M57 determine that the round’s initial target has already been defeated.

M57D 'Dirty' Smartgun[]

The M57D is an utterly vicious weapon that is sanctioned for extreme circumstances only. It fires rounds that shatter into hundreds of radioactive splinters inside their target, causing human survivors of the weapon to develop all manner of debilitating long-term health problems. It can create truly astounding radiation levels in larger targets, forcing these enemies to lose health for extended periods of time. Naturally, the upgraded Smartgunner wears radiation shielded armor as a safety precaution.

M59/B Smartgun[]

Rookie firing Smart Gun

The Rookie firing an M59/B.

In use with the USCM by the time of the incident on BG-386, the M59/B is fairly similar to the original M56, although it features an upgraded scope that will highlight all recognized threats in the weapon's field of fire; as with the M42C Scoped Rifle, these highlighted targets will be visible even through walls and other obstructions at close range.[12] The weapon will also lock its barrel in place when automatic tracking is switched off, allowing for rounds to be fired at a greater velocity.[12] While this allows for greater damage output, the drawback is that the weapon requires manual aim when in this mode. Compared to the original model, the M59/B only carries 150 rounds inside the drum. As a visual effect, the barrel overheats if the weapon is fired in a prolonged period of time.

Similar USCMC Weapon Systems[]


Aliens - Defiance -05 1

The electrolaser weapon in an M56 chassis.

Aliens - Defiance -05 2

The electrolaser weapon firing.

In issue #5 of the comic series Aliens: Defiance, an arcing electroshock weapon in what looks like an M56 chassis is shown used by a USCMC marine against Xenomorphs.

This weapon is most likely an electrolaser and also probably never went past the prototype stage as a similar weapon system has not been seen since. Also the fact that the weapon is in an M56 chassis is seemingly anachronistic as the M56 Smartgun came into service over 30 years after the events depicted in that comic series.

Non-canon Depictions[]

Aliens magazine, Vol. 2 #1[]

The original description of the M56 that appeared in the "Technical Readout" section in Aliens magazine, Vol. 2 #1 in fact lists a number of erroneous (or, at the very least, since retconned) facts about the weapon. Most obviously, the magazine states that the Smartgun is "essentially a 5 kilowatt gas-dynamic laser" powered by Liquid Metallic Suspension batteries.[13] The article goes on to describe the laser beam itself as being emitted by a fast-discharge momopolar generator, which produces a high energy pulse of one-one hundredth of a second duration in the invisible light spectrum. This beam, when focussed, instantaneously superheats the target area and creates an explosive effect capable of penetrating light armor.[13] The description of the Smartgun as a laser weapon notably matches James Cameron's original treatment for Aliens, which repeatedly describes the small arms carried by the Marines as plasma or directed energy weapons.[14] This was evidently changed for the film.

Despite the weapon's description in Aliens magazine, Vol. 2 #1, the later M56 operator's guide in issue 22 totally revised the Smartgun's mechanics, instead stating that it is a projectile weapon firing 10×28mm Caseless ammunition, similar in operation to the Pulse Rifle and more in line with what is shown in Aliens.[1] These more traditional mechanics have since been accepted as canon and the description of the weapon later included in Aliens: Colonial Marines Technical Manual, and its portrayal in numerous video games, is in line with the operator's guide from Aliens magazine, Vol. 2 #22.

Behind the Scenes[]


A pre-production sketch of the Smartgun.

The M56 Smartguns in Aliens were based on concept sketches drawn by director James Cameron, although much of the final design was created by British movie armorers Bapty & Co., who built the live-firing weapons.[15] The Smartguns were based on World War II German MG 42 belt-fed machine guns.[16] The guns were disguised with cosmetic additions, including parts from motorcycles; the rear "trigger" is a motorcycle clutch lever[15] and the "struts" on the front barrel are Kawasaki AR125 footrest hangers,[17][18] while the forward grip was a Kawasaki GPz750's left switchgear.[19] The weapon's muzzle was also extended with a specially made brake added to disguise the MG 42's distinctive bulbous muzzle. The additions were designed to give the machine gun a unique appearance whilst remaining reminiscent of real-world weaponry.[16] The weapons' distinctive operator eyepiece was modelled after contemporary helicopter pilot sights.[20]

The prop itself is over 50 inches long, although it was originally even longer — the weapon's length had to be reduced when chief armorer Simon Atherton discovered actress Jenette Goldstein, who plays Vasquez, was far shorter than he had anticipated, standing just 5'2" tall.[21] Due to the construction being primarily of metal, the weapon's significant weight created its own set of problems during filming.[16] The weapons were also very unwieldy, and as a result were physically attached to the actors using a steadicam filming harness, transferring most of the gun's considerable weight to the actors' legs while also helping to balance the weapon.[22][16] Even so, the Smartguns required careful handling by the actors at all times; at one point, Jenette Goldstein took her hands off of her weapon and, according to Atherton, it "shot out in front of her and she toppled over and landed smack on the floor".[23]

Vasquez and Drake with Smart Guns

Vasquez and Drake with their Smartguns. Note the graffiti.

In the film, the M56 was used by Vasquez and Drake, who had customized their weapons with the words "ADIOS" (on Vasquez's Smartgun) and "My bitch" (on Drake's) written on the side ahead of the charging handle.[8]

At least one of the props from the film (the one owned by the Prop Store) had the markings "ADIOS" and "bitch" on the side, one painted over the other. This is an indication that these guns were interchanged between the characters while filming, a fairly common movie practice. The same prop owned by the Prop Store has been deactivated to comply with United Kingdom firearms laws and has had some restoration to bring it back to its original condition.[16]


  • The M56's tracking mechanisms are said to be infrared in nature. However, in Aliens, the Xenomorphs are shown to be invisible to infrared scanning (similarly, Yautja are unable to detect them with their heat-based vision mode). The Smartgun should therefore be unable to track the creatures. Whilst Aliens makes it seem as though this is indeed the case — Vasquez and Drake are seen spraying wildly with the weapons whilst inside the Hive, instead of firing targeted bursts as would be expected — numerous video games portray the Smartgun as being able to track Xenomorphs with ease, which would be incorrect given what we know.
  • As well as the standard M56, Vasquez's Smartgun from Aliens is featured in the video game Aliens: Colonial Marines as a "Legendary Weapon".
  • The HUD of the M56 Smartgun in Aliens: Colonial Marines is very different from what was seen in the Colonial Marines Technical Manual, with the HUD depicted in the manual being much simpler.
  • In the Brady Games Aliens: Colonial Marines Guide the Vasquez's Smartgun section name and description use "Smartgun", despite the M56 Smartgun section and description using "Smart Gun" and the game itself using "Smart Gun" for Vasquez's M56 and the standard one.
  • The G.I. Joe Pursuit of Cobra 'City Strike" Iron Grenadier and 30th Anniversary Iron Grenadier figures come with a "Thermo-reactive anti-armor assault cannon"[24] which appears to be heavily based on the M56 Smartgun. The assault cannon uses cased rounds (like the actual prop used in Aliens) carried in an ammo box held on the bottom of the cannon or on the figure's back.[25] The front of the packaging of both figures depicts the Iron Grenadier wielding his cannon (although only a small portion of the Iron Grenadier and cannon are shown) and the back of the 30th Anniversary figure depicts the full Iron Grenadier wielding his weapon.
    • Similarly, the G.I. Joe Pursuit of Cobra "Desert Battle" Conrad "Duke" Hauser figure comes with a rifle which appears to be heavily based on the M41A design.
    • The GI Joe Convention 2013 Night Force Repeater figure also featured a weapon which appears to be heavily based on the M56. The figure's card mentions that he is a "STEADI-CAM MACHINE GUNNER"[26] indicating that the machine gun is actually supposed to be mounted on a steadi-cam as with the M56 prop used in Aliens. The weapon's sculpt is very similar (if not the same) as the Iron Grenadier's (although this one is intended to be attached to a mount) and also uses cased rounds carried an ammo box which is can be held in the same positions as the Grenadier's.




Notable users[]

Behind the scenes[]


See Also[]

External links[]


  1. 1.0 1.1 1.2 1.3 Dave Hughes, Lee Brimmicombe-Wood. Aliens, Vol. 2 #22, p. 34 (1994), Dark Horse International.
  2. 2.0 2.1 2.2 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 16 (2012), Titan Books.
  3. Andrew E. C. Gaska. Alien: The Roleplaying Game, p. 125 (2019), Free League Publishing.
  4. 4.0 4.1 4.2 4.3 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 18 (2012), Titan Books.
  5. 5.0 5.1 5.2 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 17 (2012), Titan Books.
  6. 6.0 6.1 6.2 6.3 6.4 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 21 (2012), Titan Books.
  7. 7.0 7.1 7.2 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 19 (2012), Titan Books.
  8. 8.0 8.1 James Cameron (writer and director). Aliens (1986), 20th Century Fox [DVD].
  9. Alan Dean Foster. Aliens, p. 71 (2014), Titan Books.
  10. 10.0 10.1 10.2 Lee Brimmicombe-Wood. Aliens: Colonial Marines Technical Manual, p. 20 (2012), Titan Books.
  11. 11.0 11.1  'Aliens: Dark Descent' (2023), Focus Entertainment.
  12. 12.0 12.1 Tim Bogenn. Aliens vs. Predator: Bradygames Official Strategy Guide, p. 7 (2010), DK/BradyGames.
  13. 13.0 13.1 Dave Hughes, Lee Brimmicombe-Wood. Aliens, Vol. 2 #1, p. 45 (1992), Dark Horse International.
  14. Alien II treatment (September 21, 1983) by David Giler, Walter Hill and James Cameron
  15. 15.0 15.1 Paul Taglianetti, Geoff Topping, Bob Gould. Sci-Fi & Fantasy FX #48, p. 41 (2000), Next Millennium Publishing.
  16. 16.0 16.1 16.2 16.3 16.4 "Prop Store - Smartgun prop from Aliens". Retrieved on 2013-09-18.
  17. http://forum.alienslegacy.com/viewtopic.php?f=12&t=1193
  18. http://forum.alienslegacy.com/viewtopic.php?f=3&t=792
  19. http://forum.alienslegacy.com/viewtopic.php?f=3&t=953
  20. Robert Greenberger, Kim Howard Johnson. Aliens: The Official Movie Book, p. 21 (1986), Starlog Press.
  21. Simon AthertonSimon Atherton Talks Weapons (2010), 20th Century Fox [Blu-ray].
  22. Gale Anne Hurd, Sigourney Weaver, Michael Biehn, Bill Paxton, Stan Winston, John RichardsonSuperior Firepower: Making Aliens (2003), 20th Century Fox [DVD].
  23. Paul Taglianetti, Geoff Topping, Bob Gould. Sci-Fi & Fantasy FX #48, p. 40 (2000), Next Millennium Publishing.
  24. Media:Etigback.jpg
  25. http://generalsjoes.com/reviews/2011/pursuit_of_cobra/figures/wave6/irongrenadier.html
  26. Media:Nfrcard.jpeg