The component at the center of much AR-15 customization and build projects, this part houses the fire control group, magazine well, and often integrates the buffer tube attachment point. It is the serialized portion of the firearm legally considered the “gun” itself. For example, selecting a durable and precisely machined unit contributes significantly to the overall reliability and longevity of the completed rifle.
Its quality significantly impacts the weapon’s function, accuracy, and safety. Historically, forged aluminum has been a common material due to its strength-to-weight ratio and affordability. More recently, billet aluminum and polymer options have gained popularity offering varied aesthetics, features, and price points. A well-made example offers a stable platform for all other components, ensuring proper alignment and consistent performance.
