Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only

The Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only represents a critical junction between DIY gunsmithing and precision engineering. As an unfinished lower receiver, this component is designed for the end user who requires full control over their build progression. Constructed from proprietary reinforced polymer, the RL556V3 is a direct evolution of the Polymer80 platform, integrating the Rhino profile for enhanced ergonomics and structural rigidity. For the builder seeking a true 80% platform, this lower receiver provides the necessary material mass and jig compatibility to complete a functional AR15 pattern firearm. All machining, drilling, and finishing are the sole responsibility of the purchaser in compliance with all applicable federal, state, and local laws.

Overview

The Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is a purpose-built component for the serious hobbyist and professional gunsmith. Unlike a completed receiver, this 80% lower requires the end user to remove specific material to achieve a functional state. The Rhino variant introduces an integrated trigger guard and a reinforced rear takedown pin boss, addressing common stress points found in earlier generations. This receiver is manufactured from a high-impact, glass-filled polymer formulation that resists environmental degradation and impact fatigue. The RL556V3 is compatible with standard AR15 lower parts kits and buffer tube assemblies, though no machining services are included or implied with this product. This is a raw component intended for skilled hands.

Features & Specs

Every aspect of the Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is engineered for precision and durability. The Rhino profile adds structural mass in the grip area and trigger guard, improving stability under recoil. The receiver is designed to accept standard AR15 fire control groups, pistol grips, and stocks. Machining pockets are pre-marked for drill and router guide alignment, reducing the margin for error in a home workshop environment.

• Reinforced polymer construction with glass-fiber fill for high tensile strength and impact resistance
• Integrated Rhino trigger guard eliminates separate installation and reduces potential failure points
• Pre-machined fire control pocket and trigger slot requiring final material removal by the end user
• Mil-spec buffer tube threading and rear takedown pin lug geometry for standard AR15 parts compatibility
• Dimensional tolerances held to +/- 0.005 inches on critical alignment surfaces

The receiver ships as a raw, unfinished component. No jigs, drill bits, or end mills are included. The end user assumes all responsibility for proper machining and final assembly. This polymer80 rl556v3 – rhino 80% ar15 lower receiver only is a foundational element for a custom build, not a complete firearm.

Who It’s For

This product is intended for individuals with demonstrable experience in firearms assembly and metalworking. The Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only is not a beginner’s kit. It is designed for the advanced hobbyist, the custom builder, and the professional gunsmith who demands a specific ergonomic profile and material composition. If you are familiar with end mill feeds, drill press setups, and proper deburring techniques, this lower receiver offers a blank canvas for a personalized AR15 build. The Rhino variant specifically appeals to those who prioritize a streamlined trigger guard and enhanced grip support. However, no liability is assumed for improper machining or subsequent failure. This component requires technical competence and adherence to all legal requirements regarding firearm manufacture.

• Experienced home gunsmiths with access to a drill press and router jig
• Custom builders seeking a polymer platform with integrated trigger guard geometry
• Professionals who require a lightweight, corrosion-resistant lower for competition or field use
• Individuals who understand and comply with ATF regulations regarding 80% receivers

This polymer80 rl556v3 – rhino 80% ar15 lower receiver only is not for those seeking a drop-in, ready-to-fire component. It is a project requiring time, skill, and proper tooling.

Shipping & FFL

Important legal notice regarding the Polymer80 RL556V3 – Rhino 80% AR15 Lower Receiver Only. Because this product is an unfinished 80% receiver and does not meet the definition of a firearm under the Gun Control Act of 1968, it may be shipped directly to your residential or business address without requiring transfer through a Federal Firearms Licensee (FFL). However, federal, state, and local laws vary significantly. It is the sole responsibility of the purchaser to verify that the ownership, possession, and completion of this receiver are legal in their jurisdiction. Some states and municipalities impose restrictions on the purchase or possession of unfinished receivers. By purchasing this product, you certify that you are legally eligible to own and machine a firearm component. No returns, exchanges, or refunds are accepted on 80% receivers due to legal and safety considerations. This polymer80 rl556v3 – rhino 80% ar15 lower receiver only is sold as a raw material component only. All machining must be performed by the end user in full compliance with applicable law. If you have any questions regarding your local regulations, consult a qualified attorney before purchase.

• Shipped directly to your address; no FFL transfer required in most jurisdictions
• Buyer must verify local, state, and federal legality before ordering
• No returns or exchanges on unfinished receivers; inspect upon arrival