Thank you, Daryl. It appears from your measurements that there was no choke effect happening until 2" before the muzzle. Tapered bore to be sure but, as I understand it, that was not adding to any choke that was achieved in the last 2", where the real rapid constriction occurred.
Perhaps Don could enlighten us further on fluid dynamics and how the tapering bore, entering the 2" choke area, would affect the shot. For one thing, was there any increase in velocity in the previous 24 inches ( Optimus barrels) before entering the rapid constriction area, or were the decreasing pressures, bore wall drag, and "headwind" caused by the shot column having to push air out of the bores ahead of it causing enough negative effects that any velocity gain from the tapering bore would be a net loss?
