Luth-AR® A3 Upper Receiver Parts Kit – Mil-Spec AR-15 – URPK-A3
The Luth-AR® A3 Upper Receiver Parts Kit (URPK-A3) is the definitive factory-spec component bundle required to finalize a stripped flat-top or A3-pattern AR-15 upper receiver. Known for producing high-quality, duty-grade platform components right here in the United States, Luth-AR packages this kit (859819007942) to streamline bench builds and eliminate the hassle of sourcing tiny, easily lost springs and detents from multiple vendors. It supplies every single high-tensile steel pin, spring, and sub-component required to fully assemble both the forward assist mechanism and the ejection port dust cover door assembly.
Every piece within the URPK-A3 kit is manufactured to strict military-specification dimensions, ensuring an exact, friction-free interface inside modern forged or billet 7075-T6 aluminum upper receivers. The forward assist button features classic mil-spec concentric texturing for positive mechanical thumb engagement, driven by a heavy-duty return spring to prevent manual bolt-assist binding. The ejection port door is stamped from resilient structural steel and coated in a clean, corrosion-resistant black phosphate finish, providing a solid environmental seal against mud and debris until flipped open by the reciprocating bolt carrier group. Whether you are assembling a fresh, custom build or restoring an old duty upper, this drop-in kit delivers seamless operational reliability.
Includes: (1) Mil-Spec Ejection Port Cover, (1) Ejection Port Cover Pin/Rod, (1) Ejection Port Rod C-Clip Retainer, (1) Ejection Port Cover Spring, (1) Forward Assist Button, (1) Forward Assist Spring, and (1) Forward Assist Roll Pin.
Key Features
- Complete Completion Kit: Bundles all seven individual mil-spec sub-components required to build out a bare upper receiver's functional external ports.
- True Mil-Spec Tolerances: Precision-dimensioned parts ensure seamless compatibility with standard Aero Precision, Anderson, Spike’s Tactical, or custom receivers.
- Heavy-Duty Steel Construction: Dust cover door, pins, and springs are forged from high-tensile steel to resist flexing or cracking under severe field conditions.
- Anti-Corrosive Phosphate Coating: Black oxide and manganese-phosphate treatments shield small components from sweat, rain, and aggressive cleaning solvents.
- Positive Forward Assist Return: High-tension spring prevents forward assist plunger float, ensuring it remains securely retracted during live-fire arrays.
- Proudly Made in the USA: Packaged and quality-tested by Luth-AR’s armorers to ensure zero defective parts or missing springs out of the box.
Product Specifications
- Brand: Luth-AR®
- Model: A3 Upper Receiver Parts Kit
- SKU / MPN: URPK-A3
- Platform Fitment: AR-15 / M4 / M16 Platforms (A3 Flat-Top Pattern)
- Material: Stamped Structural Steel & Stainless Spring Steel
- Finish: Matte Black Phosphate / Oxide
- Components Count: 7 Pieces Total
- Weight: 1.60 oz (0.10 lbs)
- UPC: 859819007942
