I'll disagree. I feel a re-finish and a sleeve job are vastly different. A hidden sleeve job to me is akin to restamping the numbers on a replaced Corvette motor to match the original frame. The work is being done to fool the general public....not very ethical in my opinion. A wall thickness gage is of great use, no doubt. There also is more to barrels than just wall thickness. Things like rivelling, loose ribs and bulges, which slip by many many shotgunners. The gents running that proof house inspect barrels all day long, year after year. I tend to think they may have learned something over those years. Your comments about what may have happened to an old gun since its last proof have merit. I still feel that the Brit proof system combined with some knowledge and a few gages can tell the real story. I've heard you mention poorly struck barrels in the past. I find this to be very rare. You have to really go out of your way to remove that much metal from the outside of the barrels. Most tubes that have poor wall thickness ended up that way by being bored out.
Steve

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