M4e1 5.56mm Assembled Upper Receiver W/Gen-2 Handguard & Fsb - M4e1 5.56 Assm Uppr Rcvr Gov 10.5'''' Bbl Carbine W/7''''hg & Fsb

Aero Precision's M4E1 5.56mm 10.5" Carbine Upper Receiver comes fully assembled, lacking only a bolt/carrier group and charging handle - the two most popular components for customization. At its heart is Aero's forged M4E1 receiver that combines the look of a custom billet receiver with "mil-spec" parts compatibility (including BCG and charging handle) and a proprietary attachment system for the included handguard. Aero has fitted the M4E1 5.56mm 10.5" Carbine Upper Receiver with a barrel of high-grade 4150 chrome-moly-vanadium carbon steel chambered for 5.56mm NATO ammunition, so it will safely handle civilian .223 Remington ammo too. The versatile 10 Mfg: Aero Precision