Davidson Defense Foe-Hammer w/Gauntlet Arms Brace 7.5-inch Pistol-Gas 1:8 300 BLK AR-15 Tubular Handguard Pistol Full Build Kit

Foe-Hammer w/Gauntlet Arms Brace 7.5-inch .300 Blackout AR-15 Full Build Kit

The Foe-Hammer w/Gauntlet Arms Brace is built around a 7.5-inch .300 Blackout barrel with an HBAR profile, finished in phosphate, paired with a "Panhead" billet upper receiver. It pairs a 7-inch MFFAR7 free-float smooth handguard with an AR-15 birdcage flash hider at the muzzle, running on a pistol-length gas system. A complete bolt carrier group, Mil-Spec charging handle, complete Lower Parts Kit, pistol-caliber buffer-system components, and a Gauntlet Arms polymer stabilizing brace round out the rest of the build. The lower receiver is not included, leaving the buyer to select and supply that component separately.

Key Features

• 7.5-inch .300 Blackout barrel, 1:8 twist, HBAR profile, phosphate finish
• Pistol-length gas system with micro low-profile steel gas block
• "Panhead" billet upper receiver, NOFA configuration
• .458-style ejection port
• MFFAR7 7-inch free-float smooth handguard
• AR-15 birdcage flash hider
• Gauntlet Arms polymer stabilizing brace included
• Complete Mil-Spec Lower Parts Kit and pistol-caliber buffer-system components included
• Lower receiver is not included.

Barrel and Gas System

The barrel runs 7.5 inches long, chambered in .300 Blackout and finished in phosphate with an HBAR profile. It carries a 1:8 twist rate and a 5/8x24 muzzle thread. Gas cycles back to the action through a pistol-length system, running a pistol-length gas tube and a micro low-profile steel gas block sized to a .750-inch journal.

Upper Receiver and Handguard

The upper receiver is a "Panhead" billet unit, built in a NOFA configuration and featuring a .458-style ejection port. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a 7-inch MFFAR7 handguard, a free-float smooth design.

Muzzle Device

Capping the muzzle is an AR-15 birdcage flash hider, threaded to match the barrel's 5/8x24 pattern and secured with the included 5/8-inch black crush washer.

Bolt Carrier Group and Charging Handle

A complete AR-15 bolt carrier group is included, made in the USA and listed for use across 5.56 NATO, .223 Remington, .300 Blackout, and .350 Legend. That broader listing describes the BCG itself; the barrel and chambering on this build remain .300 Blackout. A Mil-Spec AR-15 M4 charging handle rounds out the upper's operating components.

Lower Parts Kit and Buffer System

A complete Mil-Spec AR-15 Lower Parts Kit covers the fire-control and lower-control internals needed once a lower receiver is on hand. Behind it sits a heavy-duty AR-15 pistol buffer tube, holding a standard AR-15 carbine buffer weighing 3 ounces and a standard USA-made recoil spring. An AR-15 carbine castle nut and Mil-Spec AR-15/M16 receiver end plate secure the buffer tube assembly to the lower.

Stabilizing Brace

Capping off the rear of the build is a Gauntlet Arms polymer stabilizing brace finished in black. It mounts directly to the pistol buffer tube included with this kit, built specifically for pistol-configured AR platforms like this .300 Blackout build.

Follow all manufacturer instructions and safe handling practices.

Ensure compliance with all applicable federal, state, and local laws.

Lower receiver is not included.