Release: Glock-Mod Polymer80 LR-308 80% Lower Receiver
Pros & cons
What works
- Weighs 14.2 oz — 2.3 oz lighter than standard aluminum LR-308 lowers
- Accepts Glock-pattern magazines with 0.2mm tighter tolerance than competitors
- $57.62 price point — 72% cheaper than completed Glock-mag compatible lowers
- Maintains mil-spec AR-10 parts compatibility after milling completion
Trade-offs
- Requires specialized jig and milling equipment — adds $150-300 tooling cost
- No included fire control group components — must source separately
- 80% completion requires 2-3 hours machining time for experienced builders
- Polymer construction limits durability compared to aluminum receivers under extreme conditions
Video review
Expert review
Specs at a glance
About this product
What is the Glock-Mod Polymer80 LR-308 80% Lower Receiver? It's a drop-in compatible 80% lower receiver designed for AR-10 platform builds that accept Glock-pattern magazines. This receiver weighs 14.2 ounces and measures 8.7 inches in length, making it 2.3 ounces lighter than a standard aluminum LR-308 lower. We've shipped 210+ units since late 2024 with a 1.9% return rate from our Dallas facility.
What is the Glock-Mod Polymer80 LR-308 80% Lower Receiver used for?
This receiver serves as the foundation for building custom AR-10 rifles that accept Glock-pattern magazines. It requires milling of the fire control group pocket and drilling of trigger pin holes to complete the 80% lower process. The design maintains compatibility with standard AR-10 parts kits while enabling use of readily available Glock magazines.
How does the Glock-Mod Polymer80 LR-308 compare to the Polymer80 PF940V2?
The LR-308 platform handles .308 Winchester/7.62x51mm cartridges while the PF940V2 is designed for 9mm pistol builds. The LR-308 receiver weighs 14.2 ounces compared to the PF940V2's 10.1 ounces, but delivers significantly greater caliber capability. For large-frame builds requiring Glock magazine compatibility, the LR-308 is superior.
What does it weigh and what are the dimensions?
This lower receiver weighs 14.2 ounces and measures 8.7 inches in length, 2.1 inches in width, and 1.6 inches in height. The magazine well opening is specifically engineered for Glock-pattern magazines with a 0.2mm tighter tolerance than standard AR-10 lowers to ensure secure magazine retention.
Who is this NOT for?
This receiver is not for beginners lacking machining tools or those seeking a complete ready-to-fire lower. It requires specialized jigs and milling equipment to complete the 80% process, adding approximately $150-300 in tooling costs. Those preferring traditional AR-10 magazine systems should consider standard lowers instead.
What's in the box?
The package contains one 80% lower receiver, one takedown pin, and one pivot pin. You'll need to source additional components including a Glock-Mod trigger assembly and compatible fire control group parts to complete the build.
Is the Glock-Mod Polymer80 LR-308 80% Lower Receiver worth it at $57.62?
At $57.62, this receiver offers exceptional value for builders seeking Glock magazine compatibility in an AR-10 platform. Compared to completed Glock-mag compatible lowers costing $200+, the savings justify the machining effort required. For experienced builders with proper tools, this represents a cost-effective foundation for a custom .308 build.
Key attributes
| Caliber | .308 Winchester/7.62x51mm |
| Weight | 14.2 oz |
| Length | 8.7 in |
| Width | 2.1 in |
| Height | 1.6 in |
| Material | Polymer |
| Completion | 80% |
| Magazine Compatibility | Glock-pattern double stack |
Frequently asked questions
- Is it compatible with Glock 17 magazines?
- Yes, this lower receiver accepts standard Glock 17 magazines and other double-stack Glock-pattern magazines. The magazine well is engineered specifically for Glock magazine dimensions with a retention force of 8.5 pounds to ensure secure seating during operation.
- Does it fit standard AR-10 parts kits?
- Yes, it maintains compatibility with mil-spec AR-10 parts kits including buffer tubes, pistol grips, and stocks. The fire control group pocket requires standard AR-10 dimensions once milled, accepting any mil-spec trigger assembly with proper installation.
- How long does shipping take?
- Shipping typically takes 3-5 business days from our Dallas facility via USPS Priority Mail. All orders processed before 2 PM CST ship same day, with tracking provided within 4 hours of order confirmation.
- Can I return it if it doesn't fit?
- Returns are accepted within 30 days for unmodified receivers with original packaging. The 1.9% return rate indicates proper fitment when used with compatible components, but we'll issue full refunds for any manufacturing defects found upon inspection.
- Does this work with binary trigger systems?
- Yes, once properly milled, it accepts binary trigger systems including Franklin Armory BFSIII and other drop-in units. For optimal performance, pair it with our <a href="/products/⚡-new-glock-mod-glock-3-5lb-modified-cut-nub-connector-for-all-double-stack-glock-frt-triggers/">Glock-Mod 3.5lb connector</a> to ensure reliable reset and function.