Aero Precision M4E1 Built Lower Receiver (AR15 / "Cal Multi")
This Aero Precision M4E1 enhanced forged lower receiver is a billet-style AR15 foundation built on a 7075-T6 forged aluminum receiver with an anodized black finish. The M4E1 design incorporates assembly-friendly features including an integrated trigger guard, threaded bolt catch pin, upper tension screw, and a flared magwell.
This built lower includes a receiver extension/buffer tube assembly with end plate and castle nut installed, along with a pistol grip and a Ruger-marked collapsible stock.