The receiver was of drop-forged manufacture and covered in a matte finish. A firing pin safety was coupled with an independent safety. The action utilized a hammerless arrangement with locking block and side ejection of empty shells.
Barrels were of high pressure compressed steel with full choke in lengths of 28- (standard) and 30-inches. The M520 name designated an entire line of shotguns from Stevens that included the standard 12-gauge take-down form. 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 Stevens Model 520 (M520) was a pump-action slide shotgun appearing around 1910.
