About this 3D model

This is the Halo M6C from Halo 2. I have put 5 hours into just the model. I know its not the best, but i'm not the worst either. Please tell me what i need to improve on the model and I will update it.Note: This model is not 100% complete, it lacks a magazine, safety, slide lock/release, and extra details on the rear of the slide. Hope you like it! Update 1: added more detail on slide and made the grip more realistic to hold.