I have used both Duracoat and Krylon to paint guns, I find that the krylon does hold up to abuse, but only if you don't handle the painted piece for the 7 day curing time. The Duracoat however is a much better quality of paint/epoxy, but like the other fella said, if money is an issue make sure that is the route you want to go. It is also hard to remove Duracoat, say if you wanted to repaint your weapon later. Short of a sandblaster that stuff wont come off.
"Born on a mountain and raised in a cave, killing and fucking is all that I crave"...