The Radical Firearms 16 inch SOCOM 5.56mm AR rifle uses MIL-STD Upper and lower receivers along with the 15 inch RPR free float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories. Regardless if it's your first or fiftieth, a Radical Firearms AR rifle will not disappoint! The Radical Firearms RPR 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 room for accessories. Featuring a B5 Grip Type 23 pistol grip; B5 Bravo Stock with 6 positions; carbine MIL-STD buffer tube; A2 flash hider and a Chrome Moly Vanadium threaded barrel.