These lower receivers have a very small cosmetic factory blemish on the finish. The blem is on the right side of the receiver below the Aero Precision logo.
The Aero Precision M4E1 Lower Receiver delivers billet aesthetics in a forged package. This custom-designed enhanced forging is machined from 7075-T6 Aluminum and compatible with all mil-spec AR15 parts. Aero's custom design provides visual upgrades normally reserved for much more expensive billet lowers.
M4E1 Lower Receiver Improvements:
Threaded Bolt Catch Roll Pin - This allows for simple installation of the bolt catch and virtually eliminates the chance to damage the finish during installation (pin included). 1/16" Hex Key required for assembly.
Integrated Trigger Guard - This eliminates the possibility of breaking the trigger guard tabs by integrating the trigger guard into the lower, creating a stronger more rigid platform to build upon.
Upper Tension Screw - Allows users to fine-tune the fit of the upper and lower receiver using a nylon tipped tensioning set screw inserted in the grip tang of the lower receiver. This provides a tight fit with any standard AR15 upper receiver.
Threaded Takedown Pin Detent Recess - This allows users to easily install the Takedown Pin detent and spring with the use of a 4-40 set screw (no more launching detents across the room).
Increased Magwell Flare - Increased the flare of the magwell to aid in quick and efficient magazine changes.
Marked and milled to accept short-throw safety selectors, but will work with standard selectors as well.
Manufacturer: Aero Precision USA
Finish: Cerakote Flat Dark Earth
Material: 7075-T6 Forged Aluminum
Compatibility: Works with standard AR15 components and magazines