Did you see my gun posts as well? What I do is make a cylinder with 8 segments (As I suggested) Then I rotated it 22.5 so that the top of the cylinder is now flat, then I use loop cut to cut in the details.
The finished gun came out like this:
Here's the second one, without the stock (Wireframe)
Basically - your goal is to preserve detail while using as little polygons as possible. Most of your detail will be done via texturing.
As you can see, my AK-47 could still use further optimization, the clip for instance, is a bit higher poly than it needs. It could be a simple cube with some loop cuts and adjusted to form a rough clip, then textured for more detail.
I'd be more than happy to share the .blend with you, if you wish.
By the way, good job regardless, I didn't mean to be overly critical in the first post.
Also, this was my first attempt at weapon modeling in Blender:
http://forum.thegamecreators.com/?m=forum_view&t=145600&b=3
I'm not looking to join any amateur teams, nor do I take requests.