This is my first version of the Carnifex Hand Cannon from the Mass Effect Universe. It's currently a work in progress, and revisions are being made, but the files posted here should still work.
Updated 4-2-15: Updated version is here https://www.youmagine.com/designs/mass-effect-carnifex-pistol . I had the curved section reworked, and I cut it to fit on smaller print beds. A few other cosmetic changes were implemented, but most of the design remains the same. 

Updated 5-26-14: More cosmetic details have been added to the main body, and knurling has been added to the half-cylinder under the barrels. The grip has been made a more managable width, and is now only as wide as the grip on a Nerf Maverick. The rest of the gun may be narrowed after printing if it seems disporoportionate.  The curved section is still in need of being reworked, but this is as good as I can currently get it. I'll upload my current working file (version 6), if you've got solidworks 2013 or higher you'll be able to open it and see more for yourself.