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

Overview

For builders ready to move past the AR-15 platform, the polymer80 80% lower receiver and jig kit (LR-308) delivers the same precision engineering and user-centric design that defines the Polymer80 brand. This kit is engineered specifically for the LR-308 platform, providing a complete foundation for your custom large-frame build. Each kit includes the un-machined 80% lower receiver along with the dedicated jig, drill bits, and end mill necessary to complete the fire control pocket and trigger pin holes. The polymer80 80% lower receiver and jig kit (LR-308) removes the guesswork from the finishing process, giving you a repeatable, indexed jig system that aligns perfectly with the receiver blank. This is a production-grade solution for the serious hobbyist or small-volume builder.

Features & Specs

The polymer80 80% lower receiver and jig kit (LR-308) is built around a high-impact, glass-reinforced polymer frame that resists flex under recoil. The jig is constructed from hardened aluminum and steel guide plates, ensuring bit alignment remains consistent across multiple builds. The kit includes all necessary tooling, meaning you do not need to source separate drill bits or end mills. Below are the core specifications and features of this kit.

• Receiver material: glass-reinforced Nylon 66 polymer with integral trigger guard
• Compatible with standard LR-308 / DPMS pattern upper receivers and lower parts kits
• Included jig features hardened steel drill bushings and a modular clamping system for bench or vise use
• Kit contents: one 80% lower receiver, one aluminum jig, three drill bits, one end mill, and installation hardware
• FFL transfer is not required for the unfinished receiver; finishing the fire control pocket is the builder’s responsibility

Who It’s For

This kit is intended for the experienced firearm builder who demands a reliable, repeatable finishing process. The polymer80 80% lower receiver and jig kit (LR-308) is not a beginner-level product; it requires access to a drill press or a handheld drill with a steady hand, as well as familiarity with basic machining concepts such as depth control and deburring. If you have previously completed a Polymer80 80% lower for the AR-15 platform, this LR-308 version follows the same indexed jig logic but with larger dimensions to accommodate the larger-frame components. This kit is also suited for small gunsmithing operations that want to offer custom LR-308 builds without the overhead of a full machining setup. The polymer80 80% lower receiver and jig kit (LR-308) gives you the flexibility to choose every component in your build, from the trigger group to the stock and buffer system.

Shipping & FFL

Because the polymer80 80% lower receiver and jig kit (LR-308) is classified as an unfinished, non-serialized 80% receiver, it does not meet the legal definition of a firearm under federal law. No Federal Firearms License (FFL) transfer is required for shipment to your door. However, you are solely responsible for understanding and complying with all applicable federal, state, and local laws before purchasing this kit. Some states and municipalities impose restrictions on the possession, finishing, or transfer of 80% receivers. We strongly recommend verifying your local ordinances prior to ordering. Shipment is via ground carrier with adult signature required. No returns or exchanges on opened jig kits.

• No FFL transfer needed for the unfinished receiver blank
• Adult signature required at delivery
• Check your state and local laws; buyer assumes all legal responsibility
• Kit ships in a single box; jig may ship separately from the receiver in some cases