RIFLE: WISE ARMS MODEL WA-15B RIFLE, SERIAL NUMBER WA-B31336, BLUE / CCH, CASE NOT INCLUDED, SEMI - AUTOMATIC, .300 BLACKOUT, 16" Notes: Wise Arms WA-15B Rifle Comes With One Magazine Caliber: .300 AAC Blackout (.300 Whisper) Action: Semi-automatic Barrel Lengths: 16-inch Twist Rate: 1:8" Handguard: 15-inch M-LOK free-floating rail Trigger: Upgraded 3.5-pound trigger spring kit Finish: Durable Cerakote in Bronze