RL556v3 80% AR15 Lower – White | Polymer80
About this product
The Polymer80 RL556v3 is a white 80% AR-15 lower receiver designed for the builder who wants a lightweight, durable foundation for a custom rifle. It arrives unfinished, requiring you to complete the fire control group pocket, giving you full control over the final build. Since hitting our shelves in mid-2024, this has become one of our most-reordered items, with customers consistently satisfied and returning for another.
Key Highlights
- Constructed from high-strength, fiber-reinforced polymer for a durable yet lightweight frame.
- Compatible with standard AR-15 parts kits, uppers, and magazines for straightforward assembly.
- Includes a proprietary rear takedown pin spring and detent for a simplified, tool-less installation.
- Features an integrated trigger guard and flared magazine well for improved handling.
- Jig and drill bits are required to complete the lower (sold separately).
Product Details
| Model | RL556v3 |
| Material | Fiber-Reinforced Polymer |
| Color | White |
| Finish | Unfinished (80%) |
| Compatibility | Multi-Caliber AR-15 Platform |
| Weight (measured) | 6.0 oz |
| Includes | Lower Receiver, Rear Takedown Spring/Detent |
| Requires | Completion Jig, Drill Bits, AR-15 Parts Kit |
What Buyers Ask
What tools do I need to finish this 80% lower?
You will need a Polymer80 RL556v3-specific jig, a drill press or router, and the corresponding drill bits. Standard gunsmithing tools are required for installing the parts kit after the fire control pocket is milled.
Is this compatible with all AR-15 uppers?
Yes. The RL556v3 is designed to mate with standard mil-spec AR-15 upper receivers. We have tested it with a wide variety of forged and billet uppers without issue.
How does the polymer hold up to heat and stress?
The fiber-reinforced polymer formulation is engineered for the AR-15 platform. It is resistant to deformation under normal firing conditions and the stress points around the buffer tube and takedown pins are reinforced. The low return rate on this item speaks to its durability in use.
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Specs at a glance
What's in the box
- RL556v3 80% AR15 Lower – White | Polymer80