This is why I asked John Blauvelt if my compulsive scrubbing of my own .22's barrel was unnecessary. His opinion was yes. According to John, the best treatment of a rimfire bore is benign neglect. After you put lots and lots of ammo through it and find yourself overwhelmed with guilt because it's full of grease and wax and burned powder, you can run a wet patch through it and then a dry one. But nothing more than that. Most .22s, said John, don't really start to shoot accurately until you get them dirty, and as far as rust goes, when the bore is coated with lube from the bullets, the steel is sealed off from the air, so no rust.