Radical Firearms RF01674: The Radical Firearms 16\" SOCOM 5.56mm AR rifle uses MIL-STD Upper and lower receivers along with our 15\" RPR free float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories. This rifle ships with an upgraded Coyote Tan B5 Stock and pistol grip. Regardless of if it's your first or fiftieth, a Radical Firearms AR rifle will not disappoint!