Has anyone ever seen a 10 bore or bigger gun with riviling in front of the choke sections? I've seen 12's, but can't recall seeing a 10 so damaged. I believe the cause is large shot bridging which causes a gas hammer. The tendancy to bridge goes down with smaller shot size to bore diameter. I wonder if 10's are just big enough for fowling shot or if they have enough thicker barrels to resist the gas hammer. Thoughts?