Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only

If you are looking to build an AR-15 from the ground up with a solid, no-frills foundation, the Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is a strong contender. This is the same platform that has earned a reputation among home builders for its straightforward machining process and durable polymer construction. Polymer80, known for their innovative 80% designs, has refined this lower to offer a clean, functional base that works with standard mil-spec AR-15 parts kits. Whether you are a first-time builder or a seasoned enthusiast, this lower gives you the control to create a rifle that fits your specific needs without the premium price tag of a fully finished receiver.

Overview

The Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is an unfinished lower receiver that requires you to complete the remaining 20% of the machining work. It is made from a high-impact, glass-reinforced polymer that is both lightweight and impact-resistant. The design features an integrated trigger guard and a flared magazine well for faster reloads. This 80% lower is compatible with all standard AR-15 upper receivers and parts kits, making it a versatile starting point for a custom build. The RL556V3 is a direct improvement over previous Polymer80 models, with reinforced stress points and a more ergonomic grip angle. When you pick up the polymer80 rl556v3 – rhino 80% ar15 lower receiver only, you are getting a proven platform that has been used by thousands of builders across the United States.

Features & Specs

This lower receiver is built with the hands-on builder in mind. The polymer material is not just lightweight; it is also resistant to solvents and oils commonly used during cleaning. The internal pocket geometry is designed to work with standard jigs, simplifying the finishing process. Below are the key specifications and features you can expect from the Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only.

• Material: High-impact, glass-reinforced polymer that withstands repeated use and harsh environments.
• Compatibility: Accepts all standard AR-15 mil-spec parts kits, including triggers, grips, and stocks.
• Design Features: Integrated trigger guard, flared magazine well, and textured grip panels for improved handling.

Here are additional details that set this lower apart from others on the market.

• Reinforced Buffer Tower: The RL556V3 features a reinforced buffer tower to handle the stress of heavy buffer weights and full-auto rated bolts.
• Easy Marking: The receiver comes with a clear, easy-to-follow marking for the safety selector and bolt catch positions.
• Weight: Approximately 7.5 ounces, making it one of the lighter 80% lowers available for the AR-15 platform.

For those who appreciate the details, here is a quick spec list.

• Manufacturer: Polymer80
• Category: Parts (Lower Receiver)
• Finish: Black textured polymer
• Caliber: 5.56 NATO / .223 Remington (compatible with all AR-15 calibers using appropriate uppers)

Who It’s For

The Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is ideal for the DIY builder who wants to learn the mechanics of their rifle from the ground up. It is also a great choice for those who want a lightweight build for hunting, competition, or range use without sacrificing strength. Because it is an 80% lower, it is not considered a firearm by the ATF until it is finished, which means it can be shipped directly to your door without going through a licensed dealer. This makes it a popular option for hobbyists who prefer to keep their build private. However, it is important to note that once you complete the machining, you are responsible for ensuring the firearm is legal to own in your state and local jurisdiction. This lower is not recommended for those who are not comfortable with basic tools like a drill press or router, or for those who want a ready-to-go receiver out of the box.

Shipping & FFL

Because this is an 80% lower receiver, it is not classified as a firearm under federal law. This means we can ship the Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only directly to your home or business address without the need for an FFL transfer. No background check is required for the purchase of this item. However, it is your responsibility to check your local, state, and federal laws before purchasing. Some states and localities have restrictions on the ownership or manufacture of 80% receivers. We recommend consulting with a legal professional if you have any doubts. Once you complete the receiver, you may be required to serialize it or comply with other laws depending on where you live. We are not responsible for any legal issues that arise from the purchase, possession, or completion of this product. By purchasing, you confirm that you are legally allowed to own a firearm and that you will comply with all applicable laws.