I tried some of that Duracoat rattlecan. The one with the hardener built into the can that you release right before painting. For the money it costs, I'm unimpressed. Followed directions to a T regarding degreasing and prepping the surface. Did the coats even and relatively thin over several passes. I let it cure for weeks after. It looked great at first, but even after the first range day I was getting chipping from case ejection. For $45., I expected more. When I broke down the gun for a deep clean, I noticed it was even rubbing away where the plastic stock mates with the receiver. The only thing I can think of was humidity while I was applying the coats. It was summer. But still...
For now, I'd stick with grill or engine paint for DIY, but would rather just save up for a pro cerakote job.