looks sick, I'd add a bit more burnish/rough polish to the tip and edge of the bayonet blade to indicate it's been sharpened and in use, and maybe some brighter areas on the rest of the gun to really make it pop, a slightly lighter section on the pump; just think about how this gun is used, and where wear and damage would…
Your portfolio looks good. Modeling is solid. The edges on your high-polys are too sharp though. Your textures leave room for improvement. Right now you are mostly using base materials with a generic cloud texture. The edge wear and dirt looks generic too. Think more about how objects are used and where edges are getting…