SHOTGUN: CENTURION ARMS MODEL BP-12, SERIAL NUMBER 24US-20348, BLACK (MATTE), CASE NOT INCLUDED, 20, 12 GAUGE, SEMI - AUTOMATIC Notes: The Centurion BP-12 is a bullpup-style 12-gauge shotgun with a compact overall configuration. This model features a magazine-fed design and is chambered for 12-gauge with side and lower picatinny rails for accesory mounting. with flip up sights and adjustable choke