Posted by David Williamson on March 4, 2015, 6:44 pm, in reply to "Hammer's and vent's"
Gary, there is no record of any hammer guns having ventilated ribs. But you can never tell if anyone sent a set of hammer barrels back for one. The last year of production was 1934 with 4 being made.
The year of the first vent rib I believe was in 1917 with the introduction of the first Single Barrel Trap gun.