Aero Precision M4E1 AR-15 Receiver Set Black

This M4E1 receiver set features their stripped lower receiver with a integrated trigger guard and their assembled upper receiver with an enhanced forging. M4E1 Lower Receiver Features: Threaded Bolt Catch Roll Pin - Allows for simple installation of the bolt catch and virtually eliminates the chance to damage the finish during installation (pin included). Integrated Trigger Guard - 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 - Allows user 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