Davidson Defense Heirloom w/Gauntlet Arms Brace 14.5-inch Carbine-Gas 1:7 5.56 NATO AR-15 M-Lok Pistol Full Build Kit

Heirloom w/Gauntlet Arms Brace 14.5-inch 5.56 NATO AR-15 Full Build Kit

The Heirloom w/Gauntlet Arms Brace is built around a 14.5-inch 5.56 NATO barrel with an M4 profile, finished in Parkerized. It's paired with a 7000 Series optimized AR-15 upper receiver finished in Type III hardcoat black anodizing. It pairs a 12-inch Air Lite Series "Honeycomb" free-floating M-LOK handguard with an A2 GI birdcage flash hider at the muzzle, running on a carbine-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 black 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

• 14.5-inch 5.56 NATO barrel, 1:7 twist, M4 profile, Parkerized finish
• Carbine-length gas system with micro low-profile steel gas block
• 7000 Series optimized AR-15 upper receiver, Type III hardcoat black anodized
• Air Lite Series "Honeycomb" 12-inch free-floating M-LOK handguard, monolithic Picatinny top rail
• A2 GI birdcage flash hider
• Gauntlet Arms black 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 14.5 inches long, chambered in 5.56 NATO and built from 4150 chrome moly vanadium steel with a Parkerized finish and M4 profile. It carries a 1:7 twist rate and a 1/2x28 muzzle thread. Gas cycles back to the action through a carbine-length system, running a carbine-length stainless steel 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 7000 Series optimized AR-15 unit finished in Type III hardcoat black anodizing, featuring a dust cover pin feature and a flat-top Picatinny rail. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a 12-inch Air Lite Series "Honeycomb" handguard, free-floating and using an M-LOK attachment system with a monolithic Picatinny top rail running along its length.

Muzzle Device

Capping the muzzle is an A2 GI birdcage flash hider, threaded to match the barrel's 1/2x28 pattern and secured with the included 1/2-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 5.56 NATO. 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 pistol buffer tube for AR-15 and AR-style pistols, 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 black polymer stabilizing brace. It mounts directly to the pistol buffer tube included with this kit, built specifically for pistol-configured AR platforms like this 5.56 NATO build.

Follow all manufacturer instructions and safe handling practices.

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

Lower receiver is not included.