The Angstadt Arms dedicated .45 ACP AR lower receiver is designed for compatibility with all your favorite parts. The 45 ACP lower receiver accepts all aftermarket and factory .45 ACP and 10mm Glock magazines and can be assembled with Mil-Spec AR-15 parts. The Angstadt Arms .45 AR lower is machined from billet 7075-T6 aluminum. Because it is from a billet, features like a flared magwell and integral trigger guard can be machined directly into the receiver. It also features a last round bolt hold open mechanism which is not common on other PCC receivers. Build the ultimate AR45 with the Angstadt Arms 45 ACP stripped lower receiver.