The M4E1 5.56mm 18" Rifle Upper Receiver adds two important benefits to Aero Precision’s M4E1 carbine upper. First, the longer 18" barrel imparts extra velocity to the bullet with a very small addition to the rifle’s OAL. Second, the longer rifle-length gas system slows down gas velocity for gentler cycling that leads to improved reliability and reduced wear on moving parts and the receiver. The result? Rifle-like performance - and versatility - in a carbine-sized package. The Aero Precision M4E1 5.56mm 18" Rifle Upper Receiver delivers all the other benefits of Aero’s M4E1 receiver line. The bolt/carrier group and charging handle are omitted so you can customize those parts to suit your needs. (Why pay for parts you’re only going to replace anyway?) The forged M4E1 receiver has the unique appearance of a custom "billet" receiver, yet accepts standard AR-15 "mil-spec" parts.

FEATURES

• Forged 7075 T6 aluminum receiver, Mil 8625 Type 3 Class 2 hardcoat anodized
• Ejection port cover & forward assist installed
• .250" dia. pivot/takedown pin holes
• 4150 chrome-moly-vanadium barrel, 1-7" rifling, black QPQ finish
• Chambered for 5.56x45 NATO; accepts .223 Remington, too
• A2-style flash suppressor - not pinned or welded
• RIFLE-LENGTH gas system with low-profile gas block
• 15" OAL M-LOK handguard installed
• Handguard: 1.78" inside diameter clears most muzzle devices and 1.5" suppressors
• Bolt/carrier group & charging handle NOT included

The Aero Precision M4E1 5.56mm 18" Rifle Upper Receiver comes with Aero’s Gen 2 Enhanced M-LOK Handguard installed to form a solid, monolithic accessory mounting platform. The uninterrupted full-length Picatinny top rail runs from the rear of the receiver across the entire length of the 15" handguard without a gap. Plenty of M-LOK accessory attachment slots on the handguard, plus QD sling swivel sockets. Texture milled into the flats give you an excellent hold - and enhance to your gun’s unique appearance.