Barrel: Harrington & Richardson 20" 5.56 NATO 1/7 Pencil Barrel made from 4150 Chrome Moly Vanadium Steel with a parkerized finish with chrome lining. Features a Rifle Barrel Extension, 1/2"x28 threaded barrel, 1/12 twist rate, and Rifle gas system. Upper: Newly manufactured uppers forged from 7075-T6 Aluminum using proprietary NoDak Spud Dies. Finished in gray anodizing. Lower: Made from forged aluminum and equipped with the Retro H&R FCG and A1 furniture, this lower is classic in style and performs as an American Classic should.