Pros:

Certainly have a very good animations, I like how he move the mag. It makes me want to reload all the time. Textures are certainly very good, no texture misalignments to be found.Model is only around 5000 polys which is certainly what everyone with any kind of computer (old and new) needed. You made a really good rig, I wish I knew how you can do that.

Cons:

Certainly what I dont like is the origins, I think it is far too much to the right, a little unrealistic. The m9 textures could be darker. I dont like the silencer, seems too me its too long. The silencer and the gun texture have different shades of black.

Improvements:

Make a better origin, I like a little to the middle and the gun is close to the persons view. It makes it feels very light and even greater with a better sound. A better render should also be made to attract attentions

Notes:

I like your rigs, certainly they are the best. If only you can teach me how. Certainly very original, but I dont prefer it. An m9 has 15 bullets while a USP has 12, but anyway I shouldnt nag about realism :).

Certainly a 9.5/10