The Stevens Model 520 (M520) was a pump-action slide shotgun appearing around 1910. Its general form and function were highly conventional while reliability and construction held in generally high regard for the time - though some questioned the type's overall complexity. The M520 name designated an entire line of shotguns from Stevens that included the standard 12-gauge take-down form. Barrels were of high pressure compressed steel with full choke in lengths of 28- (standard) and 30-inches. The action utilized a hammerless arrangement with locking block and side ejection of empty shells. A firing pin safety was coupled with an independent safety. The receiver was of drop-forged manufacture and covered in a matte finish. The guns arrived with a wooden stock/grip unit and wooden slide. The stock was of checkered walnut with the pistol grip integrated and a rubber butt plate fitted as standard. The slide handle was also checkered for a sure grip. The M520 utilized a tubular magazine housing five total shells - a shell could be chambered, ready-to-fire, for six shell total capacity.
"Slam-firing" - the unintentional discharge of the weapon - was possible with the M520 as disconnects were not en vogue with such guns at the time. Such action could result in the user losing control of the gun or catastrophic breech explosions. This was a "quality" seen in other shotguns of the period and generally viewed as highly dangerous to the operator.
Stevens shotguns were utilized by American forces in World War 1 (1914-1918) and World War 2 (1939-1945) with some models showcasing U.S. military stamping. Militarized versions were known as "Trench Guns" for their perforated heat-shields and bayonet support. "Riot Guns" were a derivation of the norm by not featuring the bayonet lugs and shortened barrels. Other long-barreled forms were purchased as training guns for aerial gunnery (essentially "skeet shooting"). Some 35,306 Stevens M520 guns were purchased by the American government during World War 2 from 1942 into 1945.
Indeed, no other fighting force in the world went to war quite like the Americans and their deadly, short-ranged shotguns. In fact, the German Army of World War 1 directly threatened any American infantry shotgun user with immediate execution should they be captured alive. Additional wartime service covered the Korean War (1950-1953) and the Vietnam War (1955-1975).
Design of the M520 was attributed to John Moses Browning and later refined in the Stevens M620 pump-action shotgun of 1927 (detailed elsewhere on this site).