Barrel worn out?

[skip AI]

Can someone give me a few pointers into how to tell if a barrel is worn out? (besides the obvious effect on accuracy)
Visually?

cheers

[EddieHarren]

Well...., you could use a borescope and inspect the lands, grooves, throat and crown for "firecracking" or erosion. This being said, I'm looking for the person who can look through a borescope and tell me if the barrel will be shooter or not. He or She, and I are going to be rich.