Sombra's Pistol from Overwatch. Made for 3D printing & available for sale here:
https://pinshape.com/items/30352-3d-printed-sombras-machine-pistol-overwatch
or
https://www.cgtrader.com/3d-print-models/games-toys/other/sombra-machine-pistol-overwatch
The gun is scaled to just over 14" total length. Exported the parts to scale from Maya, the units should be centimeters. I have not tested the prints yet but all of the connections are very basic keys, and at most would just need a bit of sanding after printing in order to fit properly.
Enjoy!