You'd be surprised how many guns out there are actually off the face, just because a gun is tight does not mean its on the face. Most real gunsmiths who do pre-buy checks will check things like barrel wall thickness, and the integrity of internal parts, etc. Most gun owners do not have wall thickness gauges either, when buying older guns its nice to know whats happened to those barrels in the past 100+ years. Its nice to know that the internals of a gun you are buying are sound. Most people do not know how to properly take down a A&D boxlock or even what to look for when they have the gun broke down to its bits. And I'm sure you know...just because a guns barrels "ring" true doesnt mean the barrels are 100% good to go. I've seen a few barrels in my time that rang true but had rib problems, I've also seen a few that did not "ring" that were perfectly ok. If you are buying an expensive gun...it pays in the long run to have a competent gunsmith look over it.
Dustin
