RL556v3 80% AR15 Lower – Black

About this product

The RL556v3 80% AR15 Lower in Black is a forged 7075-T6 aluminum receiver blank requiring the end-user to complete the final 20% of machining. It serves as the legal, serialized foundation for a custom AR-15 build, designed specifically for builders who want to avoid FFL paperwork. This component is where your weapon system's reliability begins, requiring precise tooling and an understanding of lower receiver geometry to finish properly.

What is the RL556v3 80% AR15 Lower used for?

It's used as the unfinished, un-serialized foundation for a custom AR-15 build that you complete yourself. You must mill the fire control group pocket, install the trigger and hammer pins, and drill the selector lever hole using a compatible jig. This process legally creates a firearm for personal use without requiring a serial number from a licensed manufacturer. For a detailed guide on selecting and using the correct jig, read The Complete Guide to 80% Lower Jig Rental Programs.

How does the RL556v3 compare to the Polymer80 PF940V2 frame?

The RL556v3 offers superior long-term durability under high-volume firing schedules compared to polymer frames like the Polymer80 PF940V2. The forged 7075-T6 aluminum construction resists deformation around the buffer tube threads and takedown pin holes where polymer can wear or crack after 5,000+ rounds. For builds where absolute dimensional stability and resistance to heat soak are critical—like duty or competition rifles—the aluminum RL556v3 is the better choice, though it requires more involved machining than polymer frames.

What does it weigh and what are the dimensions?

The raw forging weighs approximately 11.2 ounces (317 grams) before any machining is performed. Its unfinished dimensions are 9.75 inches long, 2.25 inches wide at the magwell, and 1.5 inches thick through the buffer tube extension. After completing the pocket and holes, the finished weight drops to about 9.8 ounces (278 grams), making it comparable to a Mil-Spec forged lower. Pay close attention to jig alignment; for technical specifications on jig components, see 80% Lower Receiver Jig Alignment Pin Specifications.

Who is this NOT for?

This lower is not for anyone without access to a drill press, milling setup, or dedicated 80% jig system, or for builders unwilling to invest 45-90 minutes of precise machining work. It's also a poor choice for first-time builders who haven't previously assembled a complete lower from a parts kit, as mistakes during milling are irreversible and ruin the receiver. If you need a drop-in-ready foundation, consider our finished 80% Lower Fire/Safe Marked – Anodized Black instead.

What's in the box?

You receive exactly one unfinished RL556v3 80% lower receiver blank, nothing else. The box contains no jig, no tools, no lower parts kit, and no instructions—just the raw forged aluminum piece. You must source a compatible jig like the Easy Jig® Gen 2, a 5/16" end mill, drill bits, and a complete lower parts kit separately. For the correct end mill, we recommend the 5/16″ High Speed End Mill for Easy Jig® Gen 2.

Is the RL556v3 80% Lower worth it at $0?

At a $0 price, it represents a promotional entry point, but your true cost includes the $100-$250 jig rental or purchase, $40-$80 for proper tooling, and $60-$120 for a quality lower parts kit. The value proposition depends entirely on whether you plan multiple builds to amortize the jig cost. For a single build, a finished 80% lower might be more economical; for three or more builds, the RL556v3's durability and zero FFL requirement justify the tooling investment.