you are correct but their is alot of cool weapons in alot of movies and video games like Aliens and Halo on the X-Box and Doom the Movie and F.E.A.R on the PC and much much more.
They look a lot like British SA-80s with a lot of plastic casing stuck on the outside to make them look more futuristic. Likewise, the M-41A pulse rifles used in Aliens were actually only WW2 vintage Thompson 9mm SMGs with a cut down pump action shotgun stuck under the barrel for their 'Grenade Launcher'.
Another intresting bit of trivia. The M56 Smart-Gun, used in the same film were also used WW2 props: this time an MG42, spliced with a Yamaha Dirt Bike and a Camera mount. Also, more well known: Han Solo's Blaster Pistol is a C96 Mauser with a scope and cone on the muzzle acting as a break.
the Morita was in actuality a M14 rifle placed in a fiberglass bull pup stock with a ithica 12 gauge pump action shotgun mounted under Rifle barrel which used the muzzle of a M60.
Doom used modifed G36 rifles for most of the people but it did have a old .30 browning modified to look like a gatling gun.