The Rivet Gun was a new weapon based on design documentation from the original System Shock. This was a really unique design with some very challenging cuts/angles to work with, but that really added to the character of the gun. Designed as a heavy-duty industrial tool, this thing caused a lot of damage to the enemies.
Concept by Cody Williams
https://www.artstation.com/codyw
Art Direction by Kevin Manning
https://www.artstation.com/static