M41A pulse rifle

The Armat M41A is a fictional pulse-action air-cooled assault rifle used by the U.S. Colonial Marine Corps and the U.S. Army in the Alien films. In Aliens, it is described as using 10mm calibre, caseless ammunition, and is seen with an over-and-under configuration incorporating a PN 30 mm pump-action grenade launcher. The M41A props, repainted and given a different gunfire sound effect, appear at the end of Alien³. In the movie, the weapon has the fictional NATO Stock Number (NSN) 3055-00-721-4790. The M41A Pulse Rifle was designed by James Cameron and built by British armorers Simon Atherton and Andrew Fletcher from the parts and components of three firearms supplied by prop armory Bapty & Co., U.K. 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 Luigi Franchi SPAS-12 shotgun. It was... full article at wikipedia