ye. Its really nice for your first model. I think u need to think about polgons a bit more. On the barrel and grip u have used loads of unessasery ones. Its prity good though.
Utilities > More... > Polygon Counter. Make sure your model is in triangles by converting to editable mesh to get the true triangle count. I suggest adding it to your utilities button group for easy access.
I'll crit the model and give you some pointers when I have some more time later.