A good question. I can think that some of the early ones would have been this way as 14 bore was very popular for muzzle loading guns and it would mean that 14 bore tubes could be used but would neccessitate chamering to 12 bore. I suppose some would think that the constriction gave better wad obturation; then again maybe it was a passing fad. Certainly in the late 1800's Joseph Lang marketed a shotgun called the Vena Contracta which was a 12 bore tapering down to just 20 bore. It was never popular. I seem to come across quite a few hammer guns of the same era as the Stanford & Laxton gun with tight barrels of around 14 bore. Fads come and go and the current one is to overbore the barrel but then again we now have better obturating wads. Maybe someone else has a theory? Lagopus.....
