Bushmaster 300 AAC Blackout Posted January 18, 2012 in Rifles by Steve Johnson with 24 CommentsTags: .300 blk, AAC, blackout, rifle, rifles Bushmaster predictably launched a rifle chambered in .300 BLK. Bushmaster 300 AAC Blackout features a 16″ barrel with ACC Blackout muzzle brake, quad rails and Magpul furniture. Win a Kel-Tec PMR-30 !!!