The upper receiver for the AR-15 is a core component that offers a ton of flexibility to the platform (the gun as a weapon system) and to the shooter. The ability to fully customize a rifle/carbine almost completely is what has helped to build the loyal following for the AR-15 over the past 50+ years. The upper receiver provides the biggest catalyst for that custom experience. Ammunition Depot features top quality upper receivers that are made by a wide variety of top producers and feature a versatile and varied set of designs and features.