I've been told by a BR smith that .100" errosion is about all the gun will tolerate before it opens up groups and isn't competetive any more, these guys are shooting in the ones though, quarter inch groups for them don't make grade.
I'd still be happy with .250" groups though.
My dad has fired his and let it cool regularly, but for a couple times is all.
He doesn't use Danzak, I was told Danzak isn't made anymore.
Normal cleaning and a Pacnor 6 groove bbl.
I figure it will shoot good for a couple thousand rounds maybe, if the cases neck was longer, I'm told it would be into the several thousand rounds.
The barrel can be set back a number of times depending on the diameter ahead of the chamber. A straight tube has no limit, a straight taper would have a limit at some point. Not really a big deal but, does cost money still.