Davidson Defense Carapace w/Magpul BTR Brace 10.5-inch 1:10 9MM AR-9 Freefloat Quad-Rail Handguard Pistol Full Build Kit

Carapace w-Magpul BTR Brace 10.5-Inch 1-10 9mm AR-9 Freefloat Quad-Rail Handguard Pistol Full Build Kit

This is an AR-9 pistol full build kit chambered in 9mm, centered on a Bear Creek Arsenal 10.5-inch 4150 steel barrel with a black nitride finish, a 1-10 twist rate, and a direct blowback system with no gas tube or gas block. The 7075-T6 aluminum AR-15 upper receiver with a Type III hardcoat anodized finish and M4 feed ramps anchors the front end. The 10-inch freefloat quad rail handguard in black anodized 6061-T6 aluminum with a barrel nut included covers the forend. A 9mm A2 Birdcage flash hider in black at 1-2x36 closes out the muzzle end. A 9mm nitride bolt carrier group in 8620 alloy steel with an external extractor and Glock and Colt pattern magazine compatibility, and a Mil-Spec black charging handle complete the upper side. The lower completion package covers a complete Mil-Spec AR-15 lower parts kit with Mil-Spec single-stage trigger and Mil-Spec A2 grip in black, a Mil-Spec heavy-duty AR-15 6-position buffer tube, a 9mm carbine buffer, a standard AR-15 carbine recoil spring made in the USA, a Mil-Spec AR-15 and M16 receiver end plate, and a Mil-Spec AR-15 carbine castle nut. A Magpul BTR pistol brace in black polymer closes out the rear end. Lower receiver not included.

Key Features

• 9mm chambering, Bear Creek Arsenal 10.5-inch 4150 steel barrel, black nitride finish
• 1-10 twist rate, 1-2x36 thread pitch
• Direct blowback operation, no gas tube or gas block
• 7075-T6 aluminum AR-15 upper receiver, Type III hardcoat anodized, M4 feed ramps
• 10-inch freefloat quad rail handguard, black anodized 6061-T6 aluminum, barrel nut included
• 9mm nitride bolt carrier group, 8620 alloy steel, external extractor, Glock and Colt pattern magazine compatible
• Mil-Spec AR-15 charging handle, black
• 9mm A2 Birdcage flash hider, black, 1-2x36 thread pitch, black crush washer
• Complete Mil-Spec AR-15 lower parts kit with Mil-Spec single-stage trigger and Mil-Spec A2 grip, black
• Mil-Spec heavy-duty AR-15 6-position buffer tube
• AR-15 9mm carbine buffer
• Standard AR-15 carbine recoil spring, made in the USA
• Mil-Spec AR-15 and M16 receiver end plate
• Mil-Spec AR-15 carbine castle nut
• Magpul BTR pistol brace, black, polymer, Mil-Spec buffer tube compatible

Perfect For

• AR-9 pistol builders who need everything above the lower receiver for a 9mm build
• Shooters pairing this kit with an existing stripped or complete AR-9 compatible lower receiver
• Builders who want a Magpul BTR brace and a complete 9mm AR-9 pistol component set with a 10-inch freefloat quad rail handguard covered in one kit

Upper Assembly

The 7075-T6 aluminum AR-15 upper receiver with a Type III hardcoat anodized finish and M4 feed ramps forms the core of the front end. The Bear Creek Arsenal 10.5-inch 4150 steel barrel brings a black nitride finish and a 1-10 twist rate to the 9mm chamber, threaded at 1-2x36. This upper operates on a direct blowback system, meaning there is no gas tube or gas block present or required. The 10-inch freefloat quad rail handguard in black anodized 6061-T6 aluminum surrounds the barrel along the forend with four full-length Picatinny rail sections running along the top, bottom, and both sides of the handguard body for optics and accessory mounting across all four rail positions. A barrel nut is included for the handguard.

Bolt Carrier Group and Charging Handle

The 9mm nitride bolt carrier group is machined from 8620 alloy steel with a black nitride finish and features an external extractor design specific to the AR-9 blowback platform. It is compatible with both Glock and Colt pattern magazines, giving the build flexibility in magazine selection at the lower receiver level. The Mil-Spec black charging handle pairs with the BCG inside the upper receiver to complete the upper interior and finish the front end of the build.

Muzzle Device

The 9mm A2 Birdcage flash hider in black threads onto the 1-2x36 muzzle end of the barrel. The included black crush washer seats at the barrel shoulder and completes the muzzle hardware for this kit.

Lower Completion Components

The complete Mil-Spec AR-15 lower parts kit covers the full internal lower component group, including the Mil-Spec single-stage trigger, fire control group, magazine catch, bolt catch, and all associated pins and springs, with a Mil-Spec A2 grip in black covering the grip interface. The Mil-Spec heavy-duty AR-15 6-position buffer tube, 9mm carbine buffer, and standard AR-15 carbine recoil spring made in the USA form the buffer system at the rear of the lower. The Mil-Spec AR-15 and M16 receiver end plate and Mil-Spec AR-15 carbine castle nut lock the buffer tube down cleanly at the rear of the lower receiver. The Magpul BTR pistol brace in black polymer fits directly over the Mil-Spec 6-position buffer tube and closes out the rear end of the build with a well-regarded Magpul brace design that pairs cleanly with the included buffer tube.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included.