The Colt LE6921 upper in 5.56x45 NATO is a complete 14.5" carbine upper assembly built for AR-style platforms, delivering a ready-to-fire upgrade with a chrome-lined barrel, flat-top receiver, and a robust flip-up Matter-of-fact rear sight for quick target acquisition. This upper comes with a bolt carrier assembly and charging handle, plus a screw-on flash hider and a Bayonet Lug, giving you versatility for both modern sporting use and legacy accessories. The 14.5" chrome-lined barrel with a 1-7 RH twist ensures reliable performance across a wide range of 55 to 77 grain projectiles, while the included Pivot Pin Adapter enables straightforward mounting on Colt lowers with larger pivot pins. Please note the bolt carrier assembly included with this upper is current production and may not be compatible with some Colt rifles equipped with a steel sear block, so matching components ensures optimal function. Designed for AR rifles, this complete upper is ideal for builders seeking a ready-to-install upgrade that combines Colt reliability with modern enhancements for range or field use.