Original Tihar rifle from Metro 2033 game served as base for this model. Construction was changed and tuned a bit so it can actually work now. This weapon use hand-operated air pump to shoot ball-bearings. Main air tank can be pressurized up to 15 bars, which can be really deadly. This weapon is often presented as completely silent, but according my experience with pressure devices it could be as noisy as small guns.
Nice gun but a trigger mechanism is absent at all :) And on the other hand, it's really not a sketch built on something like SolidWorks. I liked very much colors and lighting.