Polymer80 80% Lower Receiver and Jig Kit (LR-308)
Take your firearms building to the next level with the Polymer80 80% Lower Receiver and Jig Kit, designed specifically for the LR-308 platform. This comprehensive kit provides everything you need to legally manufacture your own AR-10 style rifle lower receiver without the need for an FFL transfer. Crafted from high-strength polymer reinforced with steel inserts, this unfinished lower offers exceptional durability while remaining lightweight.
Complete Build Solution
This isn’t just another 80% lower – it’s a complete building system that includes the jig, drill bits, and end mill necessary to complete your receiver. The precision-engineered jig ensures perfect alignment during the machining process, making it accessible even for first-time builders. The included tooling is specifically designed for polymer receivers, providing clean cuts and professional results.
Key Features and Benefits
- High-Strength Construction: Advanced polymer composite with steel reinforcement in critical areas provides exceptional durability and impact resistance
- Complete Jig System: Includes everything needed for completion – no additional tools required
- LR-308 Compatibility: Designed specifically for AR-10/LR-308 platforms and compatible with standard DPMS pattern parts
- Legal DIY Project: Build your firearm without serialization requirements in most states (check local laws)
- Precision Engineering: Jig ensures perfect hole alignment and milling for reliable function
- Lightweight Design: Polymer construction reduces overall weight compared to aluminum receivers
Technical Specifications
The Polymer80 LR-308 lower receiver features a standard magazine well dimension that accepts .308/7.62x51mm PMAGs and other compatible magazines. The fire control group pocket is designed to accommodate standard AR-10 trigger groups, while the buffer tube threads match commercial spec tubes. The integrated trigger guard and reinforced pivot pin areas ensure long-term reliability.
Why Choose This Kit?
Whether you’re an experienced gunsmith or new to firearm building, this kit provides a rewarding project that results in a fully functional lower receiver. The satisfaction of building your own firearm combined with the cost savings over complete rifles makes this an excellent value. The polymer construction also offers corrosion resistance and maintains dimensional stability across temperature variations.
Building Process Overview
The machining process typically takes 2-3 hours with basic tools. The jig securely holds the receiver blank while guiding your drill and end mill to create the fire control group pocket and trigger pin holes. Step-by-step instructions are available from Polymer80, and numerous online resources provide additional guidance for first-time builders.
Legal Considerations
This 80% lower receiver is not considered a firearm under federal law until completed. However, builders must comply with all local, state, and federal regulations regarding firearm manufacturing. It is the responsibility of the builder to ensure compliance with all applicable laws. Once completed, the receiver must not be transferred to prohibited persons.
Why Buy From Miami Shooters Supply?
FAQ
Q: Why should I purchase from Miami Shooters Supply?
A: We are Florida’s trusted firearms supplier with extensive experience in the industry. Our team provides expert guidance on products like this Polymer80 kit, ensuring you get the right components for your build. We offer competitive pricing, fast shipping, and outstanding customer service backed by years of authority in the firearms market.
For all your firearms needs, visit our Miami Shooters Supply website.

| Platform | AR-10/LR-308 |
| Material | High-Strength Polymer with Steel Inserts |
| Completion Status | 80% Lower (Unfinished) |
| Included Components | 80% Lower Receiver, Jig, Drill Bits, End Mill |
| Magazine Compatibility | .308 PMAG and DPMS Pattern Magazines |
| Trigger Compatibility | Standard AR-10 Trigger Groups |
| Buffer Tube Thread | Commercial Spec |
| Weight | Approximately 12 oz (Receiver Only) |
| Color | Black |
| Legal Status | Not a Firearm (Unfinished) |
Frequently Asked Questions About This Product
Why buy Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform from Miami Shooters Supply?
We’re a trusted firearms dealer offering fast shipping, competitive pricing, and 100% compliance with U.S. federal firearm laws. All orders ship from our licensed facility with full tracking and expert customer service.
Where can I buy Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform?
You can purchase this item directly on our website and have it shipped to your local FFL dealer. You can also visit us in-store in Miami, Florida.
Is Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform available now?
Availability is shown live on this page. If the “Add to Cart” button is visible, this item is currently in stock and ready to ship.
What category does this product belong to?
This product is listed under: Firearms, New Arrivals, New Releases.
What tags or features does this product have?
Key features and tags for this product include: .
Is this product legal in my state?
It is your responsibility to ensure this item is legal in your state or locality. We ship only to valid FFL dealers in compliance with U.S. laws. Always check your local regulations.
FFL Transfer & Firearms Laws for Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform
All firearms, including the Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform, must be shipped to a licensed Federal Firearms License (FFL) dealer. You will be required to complete a background check and any necessary paperwork before taking possession.
How It Works
- Place your order online.
- Provide your preferred FFL dealer information.
- We ship the firearm directly to your FFL.
- You complete the background check and pickup at the FFL.
Legal Compliance
We comply with all federal and state firearm laws. It is your responsibility to ensure the Polymer80 80% Lower Receiver and Jig Kit for LR-308 Platform is legal in your state. Some states may have restrictions on certain firearm models or features.
Helpful Resources
Need assistance? Contact our Miami store for help with FFL transfers and firearm compliance.


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