The Aero Precision M4E1 Threaded Upper Receiver (brand part number APAR700201C) is a stripped AR-15 upper machined from forged 7075-T6 aluminum and finished in black anodizing, built in an angular profile that sets it apart from a standard mil-spec upper. Chambered for 5.56x45mm NATO/.223 Remington, the M4E1 is threaded to accept a standard AR-15 barrel nut and precision machined to work with the full range of mil-spec AR-15 components. It features a Picatinny top rail profile, M4 feed ramps for reliable feeding, and .250-inch takedown pin holes for a proper mil-spec fit to a compatible lower. This is a stripped, optic-ready receiver only; a dust cover, forward assist, charging handle, barrel, handguard, gas block, muzzle device, gas tube, and bolt carrier group are all required separately to complete the upper.

Key Specifications

• Chambered for 5.56x45mm NATO/.223 Remington.
• Forged from 7075-T6 aluminum.
• Finished in black anodizing.
• Machined with an angular profile distinct from a standard mil-spec upper.
• Threaded to accept a standard AR-15 barrel nut.
• Features a Picatinny top rail profile.
• Cut with M4 feed ramps for reliable feeding.
• Uses .250-inch takedown pin holes for mil-spec lower compatibility.
• Sold as a stripped, optic-ready receiver.
• Compatible with all mil-spec AR-15 parts.

Frequently Asked Questions

Does this come as a complete upper? No, it’s a stripped receiver; a dust cover, forward assist, charging handle, barrel, handguard, gas block, muzzle device, gas tube, and BCG are all needed separately to complete it.

Will it work with mil-spec AR-15 parts? Yes, it’s precision machined to work with the full range of mil-spec AR-15 components.

What material is the receiver made from? Forged 7075-T6 aluminum, finished in black anodizing.

Buy the Aero Precision M4E1 Threaded Upper Receiver

Start your build on a precision-machined, mil-spec-compatible upper. Order it from our Aero Precision lineup, part of our AR15 uppers selection, from our Lubbock, Texas gun shop as soon as it’s ready to ship.