Rare and Very Scarce Winchester Model 40 Semi Auto Shotgun Chambered in 12 Gauge, Manufactured from 1940 to 1941, They Were Winchesters Worse Shotgun Ever Made as They Blew up. The Winchester Model 40 was a short-lived American 12 gauge self-loading shotgun manufactured by the Winchester Repeating Arms Company from 1940 to 1941. Winchester's second self-loading shotgun design, the Model 40 was Winchester's unsuccessful attempt at re-entering the semi-automatic shotgun market. Winchester decided to not refine the design further and stopped production the next year in 1941. After stopping production of the Model 40, Winchester issued a recall of the firearm, although many owners of Model 40s did not take advantage of the recall reportedly, owners who did send in their Model 40s received not a repaired Model 40 from Winchester, but a Model 12 instead, along with a note telling them to "forget about Winchester making a semi-automatic shotgun", with Winchester converting most of their tooling for the war effort. The Model 40s recalled by the Winchester factory were presumably disposed of, apparently through lining them up on railroad tracks and having them run over by passing trains.