Thing is I don't like editing other peoples meshes. If I have anythings that I want to go in before I finish it I don't like breaking of parts off peoples meshes and UV wrapping them and stuff. It's just not for me. When I model I usually keeps breaks in sections where I know I will need to do some editing and I always save the mesh before fusing the parts together. So I wouldn't advise doing the 3D because I really would much rather use reference pictures.
All I need is a front,back and one side(if the gun is symmetrical, otherwise two).