This is a model of the Austringer hand cannon from Destiny, with the "broken bird, to be healed" ornament. The original STL file came from destinySTLgenerator.com, but I repaired and sized it for proper printing.
I sized this to be 265mm long, which felt about right. I have included the repaired STL file, as well as a right and left half, which is how I printed it. You can choose to slice it in other ways if you choose.
I would suggest printing the left and right half with a little bit of support around the sights, as well as the "wire" on the side of the gun, etc. It shouldn't need much and will be easy to clean up.
A note on the "dots" and numbers on the gun. These should be painted on. But I didn't feel like I could get them accurate enough freehand, so I cheated and made some 3D printed numbers and dots. I glued these on then was able to paint them. The dots are embedded in a single layer of PLA to keep them aligned. You can choose to use these extras or just paint them or do them in some other manner.