Wow quite impressive Lunar. The lineart on the grip and the front-sight are a bit off, but that's it. You may also want to add more contrast, seeing it is made of metal.

@Ergg

Thanks, this isn't completly new so I'm thinking about re-doing the shading.  (it doesn't make that much sense to me either) ;)

@withalligators

Ok, yeah I only plan to make this a single peice at the moment.  As I said above I plan to re-do the shading as I can't quite figure it out myself.  But yeah, thanks for the help.

You only AAed the outside of outline.  For practice, you ought to work on AAing the inside of the outline as well as all the details and shading on the inside.  The lighting is also hard to read.  I don't know for what purpose you made this, but if you plan on putting other sprites over any sort of moving or changing background  AA on the outside is usually unworkable.  Instead you can shade the outline or do selout (which many people really dislike [read: Helm]).

Good stuff !
It's clean. Maybe you should improve your shading but that's all I can criticize.