About this product

Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only

If you are looking to build a custom AR-15 from the ground up, the polymer80 rl556v3 – rhino 80% ar15 lower receiver only is a solid starting point. This 80% lower gives you the freedom to complete the firearm at your own pace, without the paperwork that comes with a finished receiver. Polymer80 is known in the industry for producing reliable, user-friendly frames, and this RL556V3 Rhino model continues that tradition. It is machined from high-strength polymer, designed to fit standard AR-15 parts kits, and comes ready for you to finish the milling, drilling, and assembly. Whether you are a first-time builder or a seasoned hobbyist, this lower offers a practical way to create a rifle that is truly yours.

Overview

The polymer80 rl556v3 – rhino 80% ar15 lower receiver only is an unfinished lower receiver that requires you to complete the trigger pocket, fire control group holes, and safety selector detent channel. It is compatible with mil-spec AR-15 upper receivers and parts kits, giving you flexibility in choosing barrels, handguards, stocks, and optics. The Rhino design features an integrated trigger guard and a textured grip area for better control. Because it is an 80% receiver, it does not have a serial number and is not considered a firearm by federal regulation until you complete the machining. This makes it a popular choice for builders who want to avoid serialized registration in most states, though you should always check your local laws.

Features & Specs

This lower receiver is engineered for ease of completion and reliable function. The polymer construction is reinforced with internal metal inserts at critical wear points, such as the buffer tube threads and takedown pin holes. The jig system (sold separately) guides your drill press or hand drill to ensure accurate pocket cuts.

• Material: High-impact, glass-reinforced polymer with steel trigger pin and hammer pin inserts
• Compatibility: Accepts all standard AR-15 lower parts kits and buffer tube assemblies
• Finish: Textured grip surface with an integrated trigger guard; flat dark earth or black options available
• Weight: Approximately 0.5 lbs before completion, reducing overall rifle weight compared to aluminum lowers
• Required tools: Drill press or hand drill, end mill or router, and a Polymer80 jig (sold separately)

One of the standout aspects of the polymer80 rl556v3 – rhino 80% ar15 lower receiver only is how straightforward the finishing process is. The polymer is softer than aluminum, so you can complete the pocket with standard carbide bits without excessive wear. The receiver also includes pre-marked drill points for the trigger and hammer pins, making alignment simpler for beginners.

• Pre-marked drill guides for fire control group holes and safety selector
• Metal thread inserts for buffer tube and grip screw
• Compatible with both mil-spec and enhanced trigger groups

Who It’s For

This lower is ideal for DIY builders who want hands-on experience without the cost or complexity of machining aluminum. It suits anyone who prefers a lightweight platform for home defense, hunting, or range use. The polymer80 rl556v3 – rhino 80% ar15 lower receiver only is also a good option for those who want to build multiple rifles over time without buying serialized receivers each time. Because it is an 80% receiver, you can build as many as you like for personal use, as long as you comply with federal and state regulations. It is not recommended for those who lack basic tool skills or patience, as the finishing process requires careful attention to detail.

• Home builders and hobbyists seeking a custom AR-15
• Shooters wanting a lightweight, durable lower receiver
• Individuals who prefer to avoid FFL transfers for their builds

Shipping & FFL

Because the polymer80 rl556v3 – rhino 80% ar15 lower receiver only is not a finished firearm, it can be shipped directly to your doorstep without an FFL transfer. No background check is required for the purchase. However, once you complete the receiver, you are responsible for ensuring that your build complies with all applicable federal, state, and local laws. Some states and municipalities regulate 80% receivers similarly to finished firearms. Always verify your local regulations before ordering. We ship via USPS or UPS, typically within one business day. If you have questions about your order, contact our customer service team.