The 80% AR-15 Lower Receiver in Anodized Black is the foundation of a legal, home-built AR-15 rifle. Under federal law, an 80% lower receiver is not a firearm — it is an unfinished block of aluminum that requires the completion of a small number of machining operations before it can function as a firearm. This legally allows the purchaser to complete the receiver at home using standard machining tools without a federal firearms license, so long as the completed firearm is for personal use and not for sale.
Our 80% lower receiver starts as a 7075-T6 aluminum billet, the same alloy specification used in mil-spec lower receivers by manufacturers like Colt, Daniel Defense, and Aero Precision. 7075-T6 offers dramatically higher tensile strength compared to the 6061-T6 used in budget receivers, providing confidence in the structural integrity of the completed firearm under sustained use and adverse conditions. The raw billet is CNC-machined to the exact external dimensions of a mil-spec lower receiver, including all standard features: magazine well, buffer tube threads (commercial and mil-spec compatible), front pivot pin receiver extension, rear takedown pin channel, bolt catch pocket, and magazine release recess.
The unfinished areas — the fire control group pocket and the trigger/hammer pin holes — are precisely marked with machined reference points that make completion straightforward using a drill press and end mill or a purpose-designed 80% lower jig. Multiple jig manufacturers produce compatible fixtures for this receiver, and our product page includes compatibility notes for popular options including those from 5D Tactical, Modulus Arms, and Universal Jig.
The Type III hard-coat anodize finish is applied at the 80% stage, covering all completed surfaces. The anodize penetrates the aluminum substrate rather than sitting on top like paint, creating a surface that is integral with the metal itself. Type III anodize achieves a surface hardness exceeding 70 HRC equivalent and provides excellent corrosion resistance, making the receiver ready for final finishing matching your chosen upper receiver’s finish.
Each lower is billet-serial-numbered for tracking purposes, ships with a jig compatibility guide, and includes a 12-month warranty against manufacturing defects in the pre-completed portions of the receiver. Completion of the fire control pocket voids the mechanical warranty on the finished receiver but is entirely legal for personal use. State laws regarding 80% lowers vary — it is the buyer’s responsibility to verify compliance with their jurisdiction’s laws.
