Davidson Defense Whitecap 10.5" 5.56 NATO AR-15 Pistol Build Kit, 7" Quad Rail, 1:8, w/ SBA3 Brace

Whitecap 10.5" 5.56 NATO AR-15 Pistol Build Kit, 7" Quad Rail, 1:8, w/ SBA3 Brace

Complete AR-15 pistol build kit with everything needed to assemble a functional 5.56 NATO platform except the lower receiver. The kit combines a 10.5" nitride 4150 chrome moly barrel, mil-spec upper receiver, quad-rail handguard, SBA3 brace, and all internal components for reliable operation in a compact package.

Key Features

• 10.5" nitride 4150 chrome moly barrel with 1:8 twist rate and M4 profile
• 7" four-sided Picatinny quad-rail handguard for accessory mounting
• SBA3 adjustable pistol stabilizing brace with six-position buffer tube
• Complete mil-spec bolt carrier group with nitride finish
• A2-style front sight base with gas block integration
• Carbine-length gas system for reliable 5.56 NATO cycling
• Complete lower parts kit and buffer system components included
• USA-made bolt carrier group and recoil spring

Perfect For

• Builders creating a compact 5.56 NATO pistol platform
• Shooters wanting a complete upper and lower component set
• Those seeking a quad-rail platform for tactical accessories
• Budget-conscious builders avoiding retail assembly costs
• Home builders with experience handling firearm components

SBA3 Brace Configuration

The kit ships with the SB Tactical SBA3 adjustable pistol stabilizing brace mounted on a mil-spec carbine buffer tube. The brace provides six-position length adjustment for shooters with different ergonomic needs. This configuration is designed for builders selecting their own final setup based on their intended use and local regulations. The brace compatibility with mil-spec carbine tubes ensures straightforward integration during assembly.

Quad-Rail Handguard and Accessory Ecosystem

The 7" four-sided Picatinny quad-rail handguard delivers full mounting coverage for optics, lights, lasers, and other tactical accessories. The quad-rail design distributes mounting options across all four sides of the handguard, providing flexibility for custom configurations. The 6061-T6 aluminum construction maintains lightweight handling while supporting standard AR-15 accessory weight without sagging or movement.

Barrel and Gas System Performance

The 10.5" nitride 4150 chrome moly barrel delivers velocity appropriate for compact 5.56 NATO platforms while maintaining reliability with the carbine-length gas system. The 1:8 twist rate stabilizes standard and heavier 5.56 NATO ammunition. The nitride finish protects against corrosion and wear during extended shooting sessions. The A2-style front sight base integrates the gas block, reducing component count while maintaining traditional AR-15 ergonomics.

Complete Component Assembly

The kit includes the upper receiver assembly, bolt carrier group, charging handle, complete lower parts kit, buffer tube, buffer, recoil spring, castle nut, and end plate. Lower receiver not included. All components are mil-spec compatible and designed for straightforward assembly by builders with basic AR-15 knowledge.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Ships with an SBA3 brace. Do not attach a stock unless compliant with applicable laws. Lower receiver not included.