M41A pulse rifle


 * This article refers to a fictional weapon featured in the Alien series.

The Armat M41A is a fictional weapon, a 10 mm pulse-action air-cooled automatic assault rifle, which is the basic rifle of the U.S. Colonial Marine Corps and the U.S. Army in the Alien series of films. The standard service variant has an over-and-under configuration incorporating a PN 30 mm pump-action grenade launcher.

Lightweight and rugged, the M41 is constructed largely from ultra-light alloy precision metal stampings. The outer casing is made from titanium aluminide alloy and many internal parts are molded from high-impact, temperature resistant plastics. Layout is conventional, and a spring loaded retractable stock allows the rifle to be used either in carbine format (with stock retraced) or as a rifle, with the "inline" stock extended for greater stability during automatic fire from the shoulder. Sighting is made down a groove in the carrying handle, with an adjustable tangent leaf backsight positioned in the rear slot. It has the option of mounting a rifle-sight.

Description
The M41A fires the standard US M309 10 mm x24 round. This ammunition comprises a 210 grain (13.6 gram) projectile embedded within a rectangular caseless propellant block of Nitramine 50. The propellant content is small but highly efficient, generating muzzle velocities on the order of 840 meters per second. The round is steel jacketed and explosive tipped, with impact fusing which is preset during manufacture. The round is designed to penetrate armor, exploding just after impact to inflict lethal internal damage. The standard M41 magazine will hold up to 99 M309 rounds in a "U" bend conveyor, which feeds the rounds mechanically into the rotating mechanism. However, in practice the magazines are only filled to 95% capacity in order to reduce the auto loaders tendency to jam.

The M41A is the standard service rifle of the USCM, the name derives from the electronic pulse action the rifle uses to fire off rounds. It is built from lightweight metal stampings, the exterior is composed of a titanium aluminide alloy while internal parts are composed of high durability plastics. It is additionally protected against moisture, dirt, corrosion and background radiation while remaining easy to disassemble and maintain. There is also a larger version of the M41A; the M5 pulse rifle.

The M41 uses electronic pulse action to fire, controlled directly from the trigger. The internal mechanism, including the rotating breech, is mounted on freefloating rails within a carbon-fiber jacket. From the thumb selector, the weapon can be set to selective, four-round burst or fully automatic fire, the latter allowing a rate of fire up to the weapon's cyclic rate of 900rpm. A manual cocking handle is situated in the upper receiver allows the operator to clear the breech in the event of stoppage, or to check the chamber prior to stowage.

An LED display situated just below the receiver indicates the ammo remaining in the magazine. The display can be dimmed for night operations. Power is provided by a lithium battery located in the carrying handle. The battery is good for 10,000 rounds and can be recharged either from a rifle rack or a portable power clip.

The underslung 30 mm grenade launcher comprises a barrel, breech and a four round internal magazine which is charged by handloading individual grenade cartridges in to the mechanism. A pump action is used to load rounds into the breech and cock the firing mechanism. Once loaded, the launcher is primed to fire from a trigger positioned just in front of the magazine housing, which is used as a handgrip when firing a grenade.

The most commonly used round in the grenade launcher is the M40 High Explosive fragmentation round which is marked with a red plastic cap. It has a muzzle velocity of 78 m/s, an effective range of 400 m and an accurate range of around 180 m. The cartridge has a rimmed, separating base, and launches a projectile with an explosive element comprised of a notched steel wire wrapped around a filler of composition B15. When the round explodes, it spreads more than 300 fragments over a casualty radius of five meters. The M40 can be employed as an ad hoc hand grenade flipping off its plastic cap and twisting the nose cap clockwise; this gives a five-second delay before the grenade explodes. Care must be taken not to strike or depress the nose cap, otherwise the grenade will go off immediately.

See the grenade table below for all grenades available.

Statistics

 * Ammunition: M309
 * Overall length: 69.5 cm (84 cm with stock extended)
 * Barrel length: 24.7 cm
 * Weight: 4.9 kg (with loaded magazine)
 * Rate of fire: 900 rpm
 * Fire selection: Semi-automatic, four round burst and fully automatic
 * Capacity: 99 (usually filled to 95 to prevent jamming)
 * Effective range: 500 m
 * Muzzle velocity: 840 m/s

M41AE2
A variation of this rifle is the M41AE2, which at the time of the movie Aliens was being introduced in limited numbers on a trial basis. The M41AE2 is designed as more of a light machine gun and has the following changes:
 * Grenade launcher is removed
 * Barrel is lengthened by 8 cm and made easily replaceable
 * Folding bipod is added
 * Optional L-feed magazines containing 300 rounds can be used

Prop design
The M41A Pulse Rifle that was seen in the movie was built from the parts and components of three firearms. The rifle component utilised a World War II-era Thompson M1A1 submachine gun while the grenade launcher component was built around the action of a Remington 870 pump-action shotgun and the shotgun was encased inside the shroud and foregrip of a Franchi SPAS-12 shotgun. It was originally designed around a Heckler & Koch MP5 sub-machine gun but the MP5 is said not to have produced a muzzle flash as large as desired for the impression of a futuristic infantry rifle.

The M41A Pulse Rifle looks (vaguely) like a miniature version of the USCM ship Sulaco; though the rifle was designed by James Cameron and the mother ship by Syd Mead.

There is also a conversion kit to the Tokyo Marui M1A1 Thompson airsoft gun to make it into a M41A Pulse Rifle.

Cameo appearances

 * The Pulse Rifle also makes an appearance in another James Cameron film, Terminator 2: Judgment Day, being carried by members of John Connor's resistance force. They are not featured prominently, however. In Terminator 3 T-X's on-screen display also list the M-41
 * In an episode of The Simpsons entitled The Lastest Gun in the West, a black version of this gun appears.
 * The rifle is also mentioned in the movie Soldier.
 * It is also featured in a cyberpunk comic book Breakoff, where it's mentioned by a shopkeeper in a gunshop as a great choice for the main hero of the story.
 * The models of the Pulse Rifle are shown in the Sony PlayStation game G-Police used in a few FMV cutscenes.
 * Black Versions of the M41A Pulse Rifle have been featured in one episode of the Anime Excel Saga
 * The Pulse Rifle is the weapon held by the main character on the cover of D.E. White's book Jettison
 * The Pulse Rifle is a main weapon in the Half Life mod Desert Crisis
 * The Pulse Rifle made an appearance in South Park in the ending of the episode Go, God. Go! Part II
 * It is also used in the opening FMV sequence of the expansion pack Defiance of the game I-War (Independence War). Here it is seen used by a team of marines boarding an Indie ship.
 * The Pulse Rifle can be seen briefly in one episode of the anime Galaxy Angel
 * The Pulse Rifle is used at the end of series ten episode of South Park 'Go God Go' by the otters.