The Combat Armory Billet AR-9 Lower Receiver (brand part no. STP.CA9.Lower.BLK) is a stripped lower from Combat Armory, machined from 7075 T6 aluminum billet to mil-spec dimensions. It ships with the magazine catch and ejector pre-installed from the factory and a Magpul-style trigger guard machined directly into the receiver, along with a flared magwell for faster reloads. Compatible with standard frame Glock-pattern magazines, it gives AR-9 builders a durable, precision-machined foundation without the need to source or install those small parts separately. It suits pistol-caliber carbine builders who want a solid billet lower for a 9mm AR-platform build.

Key Specifications

• Machined from 7075 T6 aluminum billet to mil-spec dimensions.
• Compatible with standard frame Glock-pattern magazines, the common magazine standard for AR-9 builds.
• Ships with the magazine catch and ejector pre-installed from the factory.
• Features a Magpul-style trigger guard machined in and a flared magwell for faster reloads.
• Finished in black for a low-profile, versatile appearance.

Frequently Asked Questions

What magazines is this lower compatible with? It is compatible with standard frame Glock-pattern magazines.

Does it come with any parts pre-installed? Yes, the magazine catch and ejector are pre-installed from the factory.

Buy the Combat Armory Billet AR-9 Stripped Lower Receiver Black

Start your AR-9 build on the Combat Armory Billet AR-9 Lower Receiver from Schaefer Defense. Browse more lowers in our AR-15 lower receivers lineup, then order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.