A good example from Printing The Revolution why 3D printing nowadays allows anyone to design and produce an airsoft rifle of any design they want, including futuristic ones... "In this video I design a futuristic bullpup concept rifle and print it on my Ultimaker 2 afterwards. I took some inspiration from some movies such as Aliens and Starship Troopers as well as the game Halo, but never looked at any specific drawings.

This airsoft was tailored to fit an existing P90 gearbox and may thus look a bit bulky. Hope you enjoy!"