I think there's generally an ad in the American Rifleman for a gunsmithing school. It's in Trinidad, Colorado, perhaps?
I'd definitely get some professional training before I got too involved. Having 50,000 psi blow up 6" from one's face would not be a good thing.
There are a lot of things like mounting sights, buttplates, and other job not involving chambering, barrels, firing pins, etc. though, that are all part of a gunsmith's job and require skill and good workmanship but aren't necessarily lethal if they're screwed up (unless the gun's owner gets really annoyed at you). Check out the Brownell's catalog (ad in American Rifleman) and buy the two volumes of "Gunsmith Kinks." LOTS of assorted information about all aspects of gunsmithing.
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