AR9 80% Lower Fire/Safe Marked – 9mm – Billet

Overview

This AR9 80% lower fire/safe marked – 9mm – billet is a precision-machined component designed for builders who require a dedicated 9mm platform without the need for magazine adapters. Constructed from 7075-T6 aluminum billet, this lower receiver is compatible with standard AR-15 LPKs and 9mm-specific upper receivers. The fire/safe markings are laser-engraved to MIL-SPEC depth and orientation, ensuring clear, permanent selector references. As an 80% lower, it requires final machining of the fire control pocket, trigger pin holes, and hammer pin holes before use. This part is not a firearm and can be shipped directly to your residence.

Features & Specs

The AR9 80% lower fire/safe marked – 9mm – billet is engineered for tight tolerances and consistent fitment with Glock-style and Colt-style 9mm magazines. The billet construction provides a denser grain structure compared to forged lowers, reducing the likelihood of stress fractures during high-round-count use. Key specifications include:

• Material: 7075-T6 aluminum billet, hard coat anodized in black to MIL-A-8625 Type III Class 2
• Markings: Laser-engraved “FIRE” and “SAFE” on both sides, with “9mm” caliber designation on the magazine well
• Compatibility: Accepts standard AR-15 trigger groups, grip, buffer tube, and 9mm bolt carrier groups
• Pocket dimensions: Pre-machined to 80% completion; requires removal of approximately 2.5 cubic inches of material for fire control group installation
• Magazine compatibility: Designed for Glock-pattern 9mm magazines with appropriate magazine catch

Additional features include a flared magazine well for faster reloads, a rear takedown pin detent hole pre-drilled to depth, and a threaded bolt catch pin hole. The fire/safe markings are positioned at 90-degree intervals for standard selector lever travel.

Who It’s For

This AR9 80% lower fire/safe marked – 9mm – billet is intended for experienced firearm builders who possess the necessary tools and knowledge to complete the 20% remaining machining. It is ideal for those who want a lightweight, low-recoil pistol caliber carbine or pistol platform without purchasing a complete firearm. The 9mm caliber is well-suited for cost-conscious shooters, competition competitors in PCC divisions, and home defense applications. Builders should have access to a drill press, vise, end mills, and appropriate jig for the 80% lower completion process. This product is not recommended for first-time builders without prior experience machining firearm components.

Shipping & FFL

Because this AR9 80% lower fire/safe marked – 9mm – billet is classified as a non-firearm receiver blank (80% complete), it does not require transfer through a Federal Firearms License (FFL) dealer. It may be shipped directly to your residential or business address via common carrier. No background check is required for purchase. However, once the lower is machined to completion, you must comply with all applicable federal, state, and local laws regarding firearm possession and serialization. Some states and municipalities have specific restrictions on 80% lowers; it is your responsibility to verify legality before ordering. By purchasing, you confirm you are not prohibited from owning firearms under federal law and that you will complete the receiver in compliance with all regulations.