The Grey Ghost Precision Cornerstone AR-15 lower receiver (brand part no. GGPC) is the starting point for a build, machined from forged 7075-T6 aluminum to tolerances tighter than mil-spec so the fit between upper and lower stays solid over years of use. Grey Ghost Precision fits a nylon-tipped tensioning screw to eliminate the wobble common on stripped lowers, and machines in a flared mag well to speed up reloads under pressure. The Cornerstone is stripped, meaning it ships as the bare receiver and requires a lower parts kit, buffer, and stock to complete the build, functioning with nearly all available AR-15 parts kits and uppers on the market. Among the receivers in the AR15 lowers category, the Cornerstone is built for shooters who want a mil-spec-plus foundation for a competition or duty-style build.

Key Specifications

• The receiver is machined from forged 7075-T6 aluminum for strength and durability.
• Tolerances are held tighter than mil-spec for a more consistent upper-to-lower fit.
• A nylon-tipped tensioning screw eliminates play between the upper and lower receiver.
• The mag well is flared for faster, more reliable magazine changes.
• Pictogram safe and fire indicators mark the selector for quick visual confirmation.
• Distinctive chevron markings are cut into the front of the mag well.
• The lower carries Grey Ghost Precision’s signature billet-style markings.
• It is multi-caliber compatible, functioning with nearly all available AR-15 parts kits and uppers.
• The lower ships stripped, requiring a lower parts kit, buffer, and stock to complete.
• It is built for semi-automatic AR-15 platforms.

Frequently Asked Questions

Does this lower ship complete or stripped? It ships stripped, so a lower parts kit, buffer, and stock are needed to finish the build.

What uppers is this lower compatible with? It functions with nearly all available AR-15 parts kits and uppers on the market.

What material is the Cornerstone lower made from? It’s machined from forged 7075-T6 aluminum to tighter-than-mil-spec tolerances.

Buy the Grey Ghost Precision Cornerstone AR-15 Lower Receiver

Tighter-than-mil-spec tolerances and a nylon-tipped tensioning screw give this lower a rock-solid foundation for any AR-15 build. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.