*Wonders if you watched that minigun tutorial of that english dude*
If you did, you thought it was hillarious as well? I did

!
Anyways yeah model is pretty plain, but cant see any errors and looks quite good, the base looks kinda boring, maybe remodel it and add to it or so thing..
Also what I do is save the render as bitmap (.bmp) then open it in Photoshop and save it with the highest jpg settings
*Edit* Just have fun when modeling, thats what I do, I dont care if I'm trying to model it from a real thing and it looks bad, I just try stuff and test and just have fun, thats why I love 3d modeling, no rules you can do what ever you want/can.
Nice model