Much smarter people then me will chime in here. That said the phrase "it depends" kicks in. If minimum barrel thickness of say .022 is located about 6-8" from the ends of the barrels that wouldn't both me much because the pressures have dropped way down by then anyway, and I'm assuming you would want to handload or shoot something like RST Lite loads where pressures are kept way down. That same .022 sure wouldn't work for me say 8" from the breech. I think halfway down the barrels you'd like to shoot for minimum of .032. Some factory small gauge Parkers were struck quite thin towards the ends of the barrel before the chokes started to kick in. PS. I had Fox early Pin Gun I purchased with some pretty significant outside pitting on the barrels. Had Dan Rossiter strike the barrels to remove the pitting and he had to take them down to .025 about 6" from the barrel ends before the rust blue. He recommended I only shoot RST ammo out of it but thought the barrels would be fine. When they get real thin they can be prone to dents from hitting just about anything (car doors, trees, etc. Ask me how I know
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