I noted the bolt action as unrealistic in one of my first responses. I never claimed an ultra-realistic shotgun. I never claimed a fully animated third person weapon. The exit for spent casing, though wrong,is barely noticeable and easily fixable.
@Dioun, my new suggestion is that you do not use this. Understandably because of it's many flaws.
Again, I'm not offended but you must admit, that you have a strange obsession with breaking this apart. I never claimed perfection but as a very first model I've ever made, it's not bad. I noticed it in that resource for WorldLab/Gamelab and sorry, it just doesn't look that out of place.
@Everyone else, I hope that this is a good base for making your own new weapons.
Edit: I'll fix the spent casing ejection and look into the texture mapping.
Edit2: I take that back, I'm leaving the shell ejection alone. This is a fantasy gun really that allows a bolt action to place a fresh round into the breach. Plus you never see the other side of the gun in first person so...I need to move on to other things.