Use Gunkote! It's not super user freindly but it'll never flake or peel and barrel heat has no effect on it. (Unless it exceeds 800 degrees!!) You can also use the Gunkote Molly finish for internal moving parts including trigger mechanisms and bolt parts. A little bit of use causes it to burnish to a perfect fit and will make it smoother than original. Acetone, cat urine, battery acid, blood, sweat and tears all have no effect on it. (Yes, we get a fair number of handguns in here that had the finish destroyed by cat urine...usually the girlfriends cat) Keep yer powder dry, Mac.
Tuff-Gun Finishes. The Name Says It All.
Mac's Shootin' Irons
http://www.shootiniron.com