IDK...Your question is a good one. I surmise a thin bbl would cool faster like a lighter projectile sheds energy.Am I ignorant to think that a thin walled shotgun barrel with rifled slugs should be allowed to cool down a lot more if the goal is legit grouping analysis?
You're missing the point.Hunting deer where you HAVE TO use a shotgun seems quite loathsome. It holds about the same appeal as changing tires with a Vice-Grip.