This paper model is a Turbo Plazma Rifel, an energy weapon that appears in Fallout and Fallout 2 video games, the papercraft was created by Morphem. The turbo plasma rifle is a modified P94 plasma rifle, resulting in an increase in the rate of fire, in Fallout this means the weapon can be fired for 1 less AP.
The P94 is a bulky, industrial-grade energy caster powered by microfusion cells. The superheated plasma bolt forms in a special chamber, then sent down a superconducting barrel and stabilized by electromagnetic claws upon exiting it.
In this version, the plasma bolt chamber has been hotwired to accelerate the bolt formation process, resulting in an increase in the rate of fire. [Source: wikia]
You can download the papercraft model template here: Fallout - Turbo Plazma Rifel Free Paper Model Download