Luth-AR LRPK-BLDR Lower Parts Kit Builder

American-Made Quality Without Compromise

Luth-AR's Lower Parts Kit Builder represents a commitment to domestic manufacturing and uncompromising quality. Every component in this kit is investment cast or machined to exacting Mil-Spec drawings, materials, and heat-treat specifications—no MIM (metal injection molding) shortcuts here.

What's Included

This builder kit provides all the essential lower receiver components you need to assemble a functional AR-15, with the exception of the grip and trigger group. This gives you flexibility to select those components based on your specific needs and preferences.

Superior Materials and Construction

Springs and Hardware: All springs are manufactured from certified 17-4 stainless steel or Mil-Spec steel wire, ensuring reliability and longevity. Full material certification provides complete traceability and confidence in every component.

Mil-Spec Compliance: Each part meets or exceeds military specifications for materials and heat treatment, delivering the same quality standard trusted by professional shooters and military users.

Built for the AR Platform

Whether you're a seasoned builder or tackling your first lower receiver assembly, Luth-AR's attention to manufacturing excellence means you're starting with components you can trust. American-made quality that performs.