FMK AR-1 Polymer Lower Receiver, 5.56 NATO

FMK AR-1 Extreme Polymer Lower Receiver

The FMK AR-1 Extreme represents a modern approach to AR-15 lower receiver design, utilizing advanced polymer materials to reduce overall rifle weight without compromising functionality or durability.

Key Features

• Lightweight Polymer Construction: Engineered polymer material reduces weight while maintaining structural integrity
• 5.56 NATO Chambering: Compatible with standard 5.56 NATO and .223 Remington ammunition
• Direct Drop-In Design: Works seamlessly with standard AR-15 upper receivers and components
• Black Finish: Professional matte black appearance
• Mil-Spec Compatible: Accepts standard AR-15 fire control groups and trigger assemblies

Design and Function

The AR-1 Extreme lower receiver serves as the serialized foundation of your AR-15 build. Its polymer construction offers weight savings beneficial for extended shooting sessions, hunting, or tactical applications. The design maintains full compatibility with aftermarket triggers, stocks, and grip panels available in the AR-15 ecosystem.

Ideal For

Builders seeking a lightweight, cost-effective lower receiver for custom AR-15 builds, competition shooters looking to reduce overall rifle weight, and shooters who value modern materials engineering in their firearms platform.