Polymer80 80% Lower Receiver and Jig Kit (LR-308)

If you are getting into building your own large-frame AR platform, the Polymer80 80% Lower Receiver and Jig Kit (LR-308) is a solid starting point. This kit gives you the main structural component plus the tooling you need to finish it yourself, without a serialized receiver going through a dealer. It is a hands-on project for anyone who wants to understand the platform from the ground up.

Overview

The Polymer80 80% Lower Receiver and Jig Kit (LR-308) is designed specifically for the large-frame AR-308 pattern. Unlike a standard stripped lower, this one comes as an 80% blank, meaning the critical fire control pocket and trigger pin holes are not yet machined. You complete those cuts at home using the included jig and basic tools. The kit includes the polymer lower receiver and a reusable jig system that guides your drill and router. It is a straightforward way to build a rifle that is entirely yours, without the paperwork and transfer fees tied to a serialized receiver.

Features & Specs

This kit is built around a glass-reinforced polymer receiver that holds up to the pressures of .308 Win and 6.5 Creedmoor loads. The jig is precision-molded to match the receiver’s geometry, so you get consistent results even if you are new to 80% builds. Here is what you get in the box:

• One Polymer80 LR-308 80% lower receiver in black polymer
• One reusable 80% jig with drill bushings and router template
• All necessary drill bits and end mill for the fire control pocket
• Stainless steel trigger pin and selector detent holes pre-marked
• Compatible with most LR-308 upper receivers and parts kits

The receiver itself uses a standard A2 grip angle and accepts standard AR-308 trigger groups. The jig clamps securely to the receiver and includes clear indexing marks so you know exactly where to cut. It is a kit that prioritizes simplicity and repeatability, which is exactly what you want when you are finishing a lower at the workbench.

Who It’s For

This kit is for the builder who wants a .308-caliber rifle without the hassle of a serialized lower. It is ideal for hobbyists who already have a drill press or a handheld router and want to try their hand at finishing a receiver from a blank. The Polymer80 80% Lower Receiver and Jig Kit (LR-308) is also a good choice if you are looking to piece together a lightweight hunting rifle or a precision build on a budget, because you are not paying for a serialized receiver or the associated transfer fee. If you have built an AR-15 lower before, the process here is similar, just scaled up for the larger LR-308 pattern. If you are new to 80% builds, the included jig and instructions walk you through each step, so you can learn as you go. This is a hands-on project for anyone who prefers assembling their own firearm over buying a complete rifle off the shelf.

Shipping & FFL

Because this is an 80% lower receiver, it is not considered a firearm under federal law. It ships directly to your door without needing to go through a Federal Firearms License (FFL) dealer. No background check or transfer paperwork is required for the receiver itself. However, once you complete the machining and assemble a functional firearm, you are responsible for complying with all federal, state, and local laws. Some states and municipalities have restrictions on 80% receivers or require serialization after completion. It is your responsibility to check your local laws before ordering. We ship this kit via standard ground service, and it typically arrives within five to seven business days. If you have any questions about shipping restrictions in your area, contact us before placing your order. We are happy to help you verify what applies to your location.

• No FFL required for the 80% receiver blank
• Ships directly to your home address
• Check local laws before ordering; some states restrict 80% receivers
• Standard ground shipping within the contiguous US