Smith Defense AR-15 Lower Build Bundle

Complete your AR-15 lower the right way with the Smith Defense AR-15 Lower Build Bundle, available from Tactical Machining. This all-in-one kit includes the Smith Defense Lower Parts Kit, Buffer Tube Kit, and Mil-Spec Stock—three essential components designed to work together seamlessly for your next AR-15 build.

Each component is built to true mil-spec standards for precise fitment and long-term reliability. From the smooth, crisp trigger pull to the secure, rattle-free stock lock-up, this bundle gives builders everything they need for a dependable lower receiver assembly.

Key Features

• All-in-One Solution: Complete lower build kit with all major components in one package.
• True Mil-Spec Fit: Engineered to exact mil-spec tolerances for reliable compatibility.
• Durable Construction: Corrosion-resistant hardware and impact-resistant polymer for long-lasting performance.
• Easy Installation: Includes all pins, springs, and small parts needed for assembly.
• Proven Reliability: Designed for consistent performance and smooth operation over thousands of rounds.

What's Included

Smith Defense AR-15 Lower Parts Kit
Mil-Spec fire-control group with polished and ground sear surfaces, Mil-Spec pin kit, Mil-Spec A2-style pistol grip (for lower build kit), Mil-Spec bolt catch, Mil-Spec trigger guard, Mil-Spec magazine catch, Mil-Spec buffer-retainer kit, and Mil-Spec selector kit.

Smith Defense Buffer Tube Kit
Mil-spec 7075-T6 aluminum 6-position carbine buffer tube, 3oz buffer, steel castle nut, steel end plate, buffer retainer, and buffer spring.

Mil-Spec Stock
Durable polymer construction with a snug, secure fit and adjustable length of pull for comfortable shooting.

Details

This bundle is the perfect solution for builders completing a Tactical Machining 80% lower or upgrading an existing rifle. Each component meets strict mil-spec standards to ensure a precise fit, smooth function, and consistent reliability. Whether it’s your first build or your next custom project, the Smith Defense AR-15 Lower Build Bundle saves time, reduces guesswork, and delivers results you can trust.

Compliance Notice

This kit contains only non-serialized firearm parts. Always check and comply with all federal, state, and local laws before assembling or installing firearm components.

Tactical Machining and Smith Defense are committed to providing builders with high-quality, mil-spec parts that deliver performance, precision, and peace of mind.