Gearbox, the guys making Aliens Colonial Marines, have been working on the game since, oh, before you were born. In that time, they've racked up a ton of reference material from James Cameron's sci-fi classic, none as badass as this replica pulse rifle from the 1986 movie.
This isn't some toy, some commercial thing made out of plastic. It's metal, it's heavy and it's "functional". Which means, yes, according to Sega it can fire live ammunition (the models used in the films only ever fired blanks).
Gearbox made it for use as a reference aid with development on the game.
It even mimics the weapons used in the films by copying their use of real-world gun parts, including components of Thompson machine guns.
It goes without saying I would like one very much.
Real-World Pulse Rifle [Sega]