The Winchester Model 1897 was the first truly successful repeating pump-action shotgun and the direct ancestor of modern pump shotguns. Designed by John Browning, the external hammer and exposed trigger allowed "slam fire" — the trigger could be held and the gun would fire with each pump stroke. Used as the US military "Trench Gun" in WWI with bayonet lug and heat shield over the barrel. German forces complained that the use of the shotgun in trench warfare violated the laws of war — a protest the US military rejected. Approximately 1 million produced from 1897 to 1957. Type: Shotgun Action: Pump-Action Caliber: 12 gauge Capacity: 6 Year introduced: 1897, USA Weight: 160 oz Overall length: 49.5" Status: Discontinued Military use: Yes Intended use: collector, historical