I modeled the AR-15 reciever in Pro/ENGENEER 2000i my senior year in high school (last year). The bullets and rendering were done in Max 5 yesterday. In total the AR prolly took 3 days or so to make (10-12 hrs) and the bullets around 2 minutes or so. Post any comments but keep then positive.
here is the render and a cellshade of it:

