Davidson Defense Marauder w/Gauntlet Arms Brace 10.5-inch Pistol-Gas 1:8 .300 BLK AR-15 Freefloat M-Lok Handguard Pistol Full Build Kit

Marauder Gauntlet Arms Brace 10.5-inch Pistol-Gas 1:8 .300 BLK AR-15 Freefloat M-LOK Pistol Full Build Kit

The Marauder is a .300 AAC Blackout AR-15 Full Build Kit built around a compact 10.5-inch pistol-length gas platform. The kit centers on a 10.5-inch HBAR profile steel barrel with a Parkerized finish, 1:8 twist rate, and 5/8x24 thread pitch, paired with a GI birdcage flash hider compatible with .300 Blackout, .308 Winchester, and 7.62x39, and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a pistol-length gas tube are included on the front end. The upper receiver is 7075-T6 aluminum with an anodized finish, M4 feed ramps, an ejection port cover assembly, and a forward assist, paired with a 10-inch freefloat M-LOK handguard in black. A USA-made complete AR-15 bolt carrier group compatible with .223 Remington, 5.56 NATO, .300 Blackout, and .350 Legend, and a Mil-Spec AR-15 M4 charging handle complete the upper side. The lower hardware includes a complete Mil-Spec AR-15 lower parts kit with a fire control group and a Mil-Spec A2 style grip in black, a heavy-duty AR-15 pistol buffer tube in black aluminum, a standard 3 oz carbine buffer at carbine length, a USA-made standard carbine recoil spring, a steel AR-15 M16 Mil-Spec receiver end plate, and an AR-15 carbine castle nut. The Gauntlet Arms polymer stabilizing brace in black is included. Lower receiver not included.

Key Features

• 10.5-inch HBAR profile steel barrel, Parkerized finish, 1:8 twist, 5/8x24 thread pitch, .300 AAC Blackout
• Pistol-length gas system
• Pistol-length gas tube
• Micro low-profile steel gas block, 0.750
• GI birdcage flash hider, 5/8x24, .300 Blackout and .308 Winchester and 7.62x39 compatible, black crush washer included
• 7075-T6 aluminum upper receiver, anodized, M4 feed ramps, ejection port cover assembly, forward assist
• 10-inch freefloat M-LOK handguard, black
• USA-made complete AR-15 bolt carrier group, .223 and 5.56 NATO and .300 Blackout and .350 Legend compatible
• Mil-Spec AR-15 M4 charging handle
• Complete Mil-Spec AR-15 lower parts kit, fire control group included, Mil-Spec A2 style grip, black
• Heavy-duty AR-15 pistol buffer tube, black aluminum
• Standard carbine buffer, 3 oz, carbine length
• Standard carbine recoil spring, made in USA
• Steel AR-15 M16 Mil-Spec receiver end plate
• AR-15 carbine castle nut
• Gauntlet Arms polymer stabilizing brace, black

Perfect For

• Builders sourcing a complete .300 AAC Blackout AR-15 pistol full build kit with a USA-made BCG and Gauntlet Arms brace already included, pairing it with their own lower receiver
• Shooters building a compact 10.5-inch .300 BLK pistol-gas platform who want the BCG, pistol buffer tube, and Gauntlet Arms brace covered in one kit with a 10-inch freefloat M-LOK handguard
• AR-15 builders who want a .300 BLK HBAR barrel with a complete lower parts kit and pistol buffer tube included without sourcing components separately

Barrel and Muzzle Device

The 10.5-inch HBAR profile barrel is chambered in .300 AAC Blackout with a Parkerized finish, 1:8 twist rate, and 5/8x24 thread pitch. The GI birdcage flash hider is compatible with .300 Blackout, .308 Winchester, and 7.62x39 at the 5/8x24 thread pitch. A micro low-profile steel gas block at 0.750 diameter and a pistol-length gas tube cover the front end gas configuration on this pistol-length platform. A black crush washer is included with the muzzle device.

Upper Receiver and Handguard

The 7075-T6 aluminum upper receiver carries an anodized finish with M4 feed ramps, an ejection port cover assembly, and a forward assist. The 10-inch freefloat M-LOK handguard is black with M-LOK attachment points along the body for accessory mounting. These two components define the exterior structure of the upper assembly on this .300 BLK platform.

Bolt Carrier Group and Charging Handle

The USA-made complete AR-15 bolt carrier group is compatible with .223 Remington, 5.56 NATO, .300 Blackout, and .350 Legend. A Mil-Spec AR-15 M4 charging handle is included to complete the upper component set.

Lower Parts Kit and Buffer System

The complete Mil-Spec AR-15 lower parts kit covers the internal lower receiver components and includes a fire control group and a Mil-Spec A2 style grip in black. The buffer system includes a heavy-duty AR-15 pistol buffer tube in black aluminum, a standard 3 oz carbine buffer at carbine length, a USA-made standard carbine recoil spring, a steel AR-15 M16 Mil-Spec receiver end plate, and an AR-15 carbine castle nut. The Gauntlet Arms polymer stabilizing brace in black rounds out the kit, providing a rear interface for the pistol platform.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included. Verify local and state laws regarding pistol brace use and classification.