Shop › BAD 16 UPPR WRKHORSE 556 AMBI BLK BAD 16 UPPR WRKHORSE 556 AMBI BLK $659.98 Battle Arms Development WORKHORSE, Complete Upper Receiver, 556NATO, 16" Barrel, Fits AR-15, M-Lok Handguard, Anodized Finish, Black, Includes Bad Rack-15 Ambidextrous Charging Handle and AR15/M16 BCG WH-UR16B-Y-15 Quantity: Add To Cart Added! Battle Arms Development WORKHORSE, Complete Upper Receiver, 556NATO, 16" Barrel, Fits AR-15, M-Lok Handguard, Anodized Finish, Black, Includes Bad Rack-15 Ambidextrous Charging Handle and AR15/M16 BCG WH-UR16B-Y-15