Features:The RDB? is the new definition of bullpup. Its downward shell ejection system eliminates the side ejection disadvantage of ordinary bullpups. The result is brass and gas that eject out of your line of sight making it a truly ambidextrous high performance rifle for everyone. The RDB is also adjustable for a wide variety of ammunition and makes for an excellent suppressor host. It?s definitely the bullpup done right.Specifications: Caliber: .223Rem /5.56x45mm Weight Unloaded: 6.9lbs/3.1kg Magazine Capacity: 10 or any AR15 compatible magazine Overall Length: 30.4?/771.5mm Barrel Length: 20.5?/520.7mm Twist Rate: 1:7?/1:177mm Trigger Pull: 4-6lbs/1.8-2.7kg