RIFLE: DIAMONDBACK FIREARMS MODEL DB15 RIFLE, SERIAL NUMBER DB2628266, BLACK (MATTE), CASE NOT INCLUDED, SEMI - AUTOMATIC, 5.56MM, 16 Notes: The Diamondback Firearms DB15 is a semi-automatic rifle chambered in 5.56mm, with a 16-inch barrel and matte black finish. The firearm is identified as a DB15 model and should be documented according to the markings and configuration present on the individual example. Item details Manufacturer: Diamondback Firearms Model: DB15 Type: Rifle Action: Semi-automatic Caliber: 5.56mm Barrel length: 16 inches Finish: Black, matte