Kel-Tec RDB 5.56mm NATO 20in Blued Semi Automatic Modern Sporting Rifle - 20+1 Rounds - The Kel-Tec RDB is truly the product of forward thinking by the engineers at the Kel-Tec R&D division. This bullpup rifle is truly revolutionary thanks to the downward shell ejection system which eliminates the side ejection system typically found on other bullpup designs. Additional the RDB bullpup rifle features an adjustable system making it great to use with a wide variety of ammunition from .223 Remington up to 5.56 NATO. Moreover the RDB can serve as an excellent host platform for individuals who already own a suppressor and wish to suppress the bullpup platform providing you with a shorter overall length rifle great for hunting or personal protection. The RDB is compatible with all standard pattern AR-15 magazines.