- "I wanna introduce you to a personal friend of mine. This is an M41A Pulse Rifle. Ten millimeter, with over-and-under thirty millimeter pump action grenade launcher."
- ―Cpl. Hicks introduces the Pulse Rifle to Ellen Ripley.
The M41A Pulse Rifle is a pulse action, air cooled, select-fire assault rifle manufactured by Armat Battlefield Systems. It is the standard issued assault rifle of the United States Colonial Marine Corps and United States Army and was used in engagements with both Yautja and Xenomorphs alike.
Based on the Weyland Storm Rifle and Harrington Automatic Rifle, the M41A Pulse Rifle is was first introduced by 2171 which became the standard issued assault rifle of the US Army and Colonial Marine Corps.
The M41A Pulse Rifle is composed of extremely light weight precision metal stampings, titanium aluminide alloy outer casing and high-impact and temperature resistant plastics for many internal parts. It's fully sealed against corrosion, dirt and moisture with it's electronics are hardened against TREE and background radiation and therefore making it perfectly usable in a vacuum. On it's own, the rifle weighs 3.2 kg but with a fully loaded magazine, being built around a 24.7 cm long barrel and sling, increasing it's weight to 4.9 kg.
Controlled directly from the trigger, the pulse rifle's fire action is thanks to an electronic pulse action. The internal mechanism plus including the rotating breech is mounted on free-floating rails within a carbon-fiber jacket and the entire assembly is recoil dampened to reduce the effects of muzzle climb during burst and fully-automatic fire. Even with the recoil reduced, it is still rather significant. The weapon also features a thumb selector, allowing the shooter to select between a 4 round burst and full automatic fire. In the event of a stoppage, a manual cocking handle on the right hand side of the receiver allows the user to check for rounds in the chamber or clear the breech in the event of a stoppage. It has a magazine capacity of 99 rounds in a 'U' bend conveyor, although the magazine weighs 1.5 kg soldiers practiced loading their magazines with a maximum of 95 rounds which prevent the weapon from jamming.
The pulse rifle mounted an underslung U1 pump-action Grenade Launcher, comprising of a breech, barrel and 4 round internal magazine. It's triggering mechanism is in front of the rifle's magazine weld. The weapon's grenade launcher needs to be hand loaded before being used.
The weapon's standard sights are made down a groove atop the carrying handle, featuring an adjustable tangeant leaf backsight in the rear aperture. For under low light conditions and accuracy at various ranges, the weapon can be fitted with a 3x power AN/RVS-52 CCD television sight. It also features a spring-loaded extendable stock that can be used in either a carbine or rifle format and features an LCD ammunition counter on the shooter's right hand side just below the receiver. The receiver is designed for quick glances as to how much ammo the shooter has left before reloading and the brightness of the weapon can be dimmed for night time operations. The weapon features a lithium battery to power for the motor mechanism which is good for 10,000 rounds before needing to be recharged from a rifle rack or portable power pack.
The vent holes of the pulse rifle are various. Usually there's a maximum of 8, however later models can have as many as 5, 9 and even 10.
- "Lieutenant, what do those Pulse Rifles fire?"
"10 millimeter explosive-tip caseless. Standard light armor-piercing round, why?"
- ―Lt. Gorman & Ellen Ripley discussing the pulse rifle's ammunition.
The M41A Pulse Rifle's primary ammunition is a 10×24mm explosive tipped caseless standard light armor piercing round designated an "M309" that is embedded in a rectangular propellant block of Nitramine 50. Despite it's small amount, it's highly efficient generating cyclic rates of 840 rounds per minute. The round is optimized for lethality against infantry wearing personal armor featuring a factory pre-set fuse that is designed to explode upon armor penetration, inflicting maximum damage. Despite the round's effectiveness against armored infantry, it surprisingly doesn't work as well when used on unarmored enemies due to it's fuse not detonating upon impacting soft targets and in turn leaving the victim unscathed necessitating the use of multiple hits to score a kill.
For the standard underslung secondary U1 grenade launcher's ammunition is the M40 High Explosive Dual Purpose (HEDP) Grenade which can also act as a hand grenade as well. It features two sections, a rimmed separating base and a metal casing topped with a red plastic identifying cap. When fired, it's base propels the casing from the barrel with a velocity of 78 m/s. The effective range of the grenade is 400 meters with an accurate range of 180 meters. The main projectile houses notched steel wire wrapped around an explosive core of Composition B15. This explosive core spreads 300 metal fragments over a casualty radius of 5 meters upon detonation.
- The M41A Pulse Rifle was made from a Thompson M1A1 submachine gun acting as the primary machine gun and a cut down Remington 870 shotgun acting as the grenade launcher.