Polymer80 LR-308 80% Lower Receiver

If you are looking to build a large-frame AR platform from the ground up, the polymer80 lr-308 80% lower receiver is a solid starting point. It is machined from a high-strength polymer blend that keeps weight down without sacrificing the rigidity you need for a .308 build. This receiver is designed for the LR-308 platform, meaning it is compatible with standard DPMS-pattern parts, so you can source your upper, barrel, and bolt group without hunting for proprietary components.

What sets this polymer80 lr-308 80% lower receiver apart is the attention to the jig interface. The receiver is molded with locating features that align perfectly with the Polymer80 jig, making the finishing process straightforward. Whether you are a first-time builder or have a few AR builds under your belt, the polymer material is forgiving to work with—it drills and routes cleanly with standard tools.

Overview

The polymer80 lr-308 80% lower receiver is a blank that you finish at home. It requires drilling the trigger pocket, selector detent hole, and rear takedown pin detent hole, plus routing the fire control pocket to spec. Once completed, it accepts all standard LR-308 lower parts kits and stocks. The polymer construction means no corrosion concerns and a noticeably lighter finished rifle compared to aluminum lowers.

Features & Specs

• Manufacturer: Polymer80 | Category: Parts | Platform: LR-308 (DPMS pattern)
• Material: Impact-modified engineering polymer with glass-fiber reinforcement
• Compatibility: Accepts standard AR-308 lower parts kits, buffer tubes, and pistol grips

This receiver also includes a threaded rear takedown pin detent hole for easy assembly and disassembly. The trigger guard is integrated into the lower, which eliminates one more part you need to source. The magwell is slightly flared for smoother reloads, and the rear lug pocket is reinforced to handle the recoil of .308 cartridges.

Who It’s For

This polymer80 lr-308 80% lower receiver is ideal for the hands-on builder who wants a lightweight .308 platform without the price tag of a complete rifle. It suits anyone comfortable with basic shop tools—a drill press and a router or a hand drill with a jig—who wants the satisfaction of completing their own firearm. It is also a good choice for shooters who plan to customize their build extensively, since you can choose your own trigger, stock, and upper components.

If you have previously built an AR-15 from an 80% lower, the process for the LR-308 is very similar, just scaled up slightly. The polymer material reduces the chance of galling during assembly, and the receiver’s geometry is designed to minimize stress points under heavy recoil. It is not a race-ready competition lower, but it is a reliable, cost-effective foundation for a hunting or range-use large-frame rifle.

Shipping & FFL

Because this is an 80% lower receiver, it is not classified as a firearm by the ATF. It can be shipped directly to your home or business with no FFL transfer required. No background check is needed for purchase. However, once you complete the receiver, you are responsible for complying with all federal, state, and local laws regarding firearm ownership and serialization. We recommend checking your local regulations before ordering.

We ship all orders within one to two business days via a carrier with tracking. The receiver ships in a plain box with no external markings indicating contents. If you have any questions about compatibility or the finishing process, our support team knows this platform inside and out and is happy to help.