20" Bull Barrel Upper For AR-15 RiflesThe bull barreled rifle is noted for it’s incredible accuracy and rightly so. Made with a Wilson Stainless Steel Barrel, This Barreled Upper comes with standard flattop upper, freefloat hand guards, and a picatinny gas block. Bull Barrels are available in 1x8 or 1x10 twist, and in 16 “, 20”, 22”, and 24” lengths. This Barreled Upper comes fully assembled with the options you choose. All barrels are chambered in 5.56mm NATO Spec.