Just saw a post on Mauser Central where a guy was complaining about it. Said he used good metal prep and after 2 weeks in a controlled temp room, finish is chipping off. He didn't go into the specifics of his metal prep and I have no experience with it. The guys seem to be doing real good work with inexpensive air brushes and Dura Coat type products. I don't know how you could properly degrease without stripping the gun and it would seem to me that this would be a problem with any spray on product. For nasty stuff I use kero and blow it out with air, then brake clean and polish, beatblast as usual prior to blueing or parkerizing.