Polymer80 LR-308 80% Lower Receiver

The Polymer80 LR-308 80% lower receiver represents a critical starting point for builders seeking a custom large-frame AR platform. Designed for the .308 Winchester / 7.62 NATO cartridge family, this 80% lower receiver requires final machining to complete, placing full control of the firearm’s legal construction in your hands. As a direct commercial offering from Polymer80, this component bridges the gap between raw material and a functional firearm, allowing you to spec every other component to your exact requirements.

Overview

This Polymer80 LR-308 80% lower receiver is engineered to accept standard LR-308 / DPMS pattern upper receivers and parts kits. The 80% design means the fire control pocket, trigger pin holes, and hammer pin holes are not fully machined, requiring the end user to complete these operations with a jig and tooling. Polymer80’s proprietary composite material offers a balance of weight savings and structural integrity, making this an ideal foundation for a lightweight hunting rifle or a precision long-range build. The receiver is compatible with most aftermarket triggers, stocks, and grips, provided they adhere to the LR-308 specification.

Features & Specs

Every Polymer80 LR-308 80% lower receiver is manufactured to tight tolerances, ensuring reliable fitment with quality upper receivers and lower parts kits. The receiver body includes all necessary reinforcement ribs at stress points, and the magwell is flared for efficient magazine changes. Key specifications include:

• Material: Proprietary reinforced polymer composite, impact and chemical resistant
• Platform: LR-308 / DPMS pattern, compatible with .308 Winchester and 6.5 Creedmoor uppers
• Finish: Textured black, non-reflective matte surface for reduced glare
• Dimensions: Standard LR-308 profile, accepts AR-10 pattern buffer tubes and stocks
• Weight: Approximately 8.5 ounces, significantly lighter than aluminum counterparts

The Polymer80 LR-308 80% lower receiver also features a removable rear takedown pin detent pocket and an integrated trigger guard, eliminating the need for a separate trigger guard component. The receiver is drilled and tapped for a standard pistol grip, and the buffer tube threads are cut to mil-spec dimensions for compatibility with commercial and mil-spec buffer tubes.

• Integrated trigger guard simplifies assembly and reduces parts count
• Reinforced front pivot pin lugs for enhanced durability under recoil
• Compatible with standard LR-308 lower parts kits, no proprietary components required

Who It’s For

The Polymer80 LR-308 80% lower receiver is intended for experienced builders who possess the tools and knowledge to complete the machining process. This product is suited for the following individuals:

• DIY firearm enthusiasts seeking a legally unregulated starting point for a large-frame AR build
• Hunters who want a lightweight, customizable .308 or 6.5 Creedmoor rifle without paying a premium for a complete factory firearm
• Competition shooters building a precision gas gun with specific trigger, stock, and handguard preferences
• Gunsmiths and hobbyists who enjoy the challenge of finishing an 80% receiver to exacting standards

This is not a product for first-time builders or those without access to a drill press or router jig. The Polymer80 LR-308 80% lower receiver requires a dedicated jig (sold separately) and basic machining skills to complete the fire control pocket and pin holes. If you are confident in your ability to follow dimensional drawings and use power tools safely, this receiver offers a cost-effective path to a custom large-frame rifle.

Shipping & FFL

This Polymer80 LR-308 80% lower receiver is classified as a non-firearm component under federal law because it is not yet a completed receiver. As such, it may be shipped directly to your residence without requiring transfer through a Federal Firearms License (FFL) dealer. However, you must comply with all applicable state and local laws regarding the possession and completion of 80% receivers. Some states and municipalities have specific restrictions, registration requirements, or outright prohibitions. It is your responsibility to verify legality in your jurisdiction before ordering. Once you complete the machining process, the resulting firearm must comply with all federal and state regulations, including any applicable serialization requirements. No refunds or exchanges will be issued for failure to comply with local laws.