mr. chipmunk,
The slight bend in the overall image is from the camera focal length. This is a common warping that happens in real cameras and though was unintentional here, it's purpose is to add perspective to an otherwise flat image.
The gun is very long so to actually get the full shape of it would require a high focal length. which I will try today. I was told good things about the rendering program marmoset toolbag which I used to make these images, honestly though, I wasnt that impressed. I like maya's viewport 2.0 much more for realtime rendering.