#html-body [data-pb-style=H8EVVKV]{justify-content:flex-start;display:flex;flex-direction:column;background-position:left top;background-size:cover;background-repeat:no-repeat;background-attachment:scroll}Barrel: Harrington & Richardson 20" 5.56 NATO 1/12 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, 1/7 twist rate, and Rifle *** 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. These exclusive retro rifles are a throwback to the late 60's era 604s that features a Gray anodized slick-sided upper receiver with a 20" parkerized 5.56 NATO barrel. The rifle length gas system and C158 BCG are paired to ensure smooth cycling and maximum durability. The later model 604 rifles also featured a mil-spec "birdcage" style A2 muzzle brake rather than the 3 prong brakes used on the previous versions.