Davidson Defense Heirloom SBR Ready 14.5-inch Carbine-Gas 1:7 5.56 NATO AR-15 M-Lok Pistol Full Build Kit

Heirloom SBR Ready 14.5-inch 5.56 NATO AR-15 Full Build Kit

The Heirloom SBR Ready Full Build Kit 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, and carbine buffer-system components are all included. The lower receiver is not included, and this SBR Ready version ships without a brace.

Key Features

• SBR Ready design
• 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
• Complete Mil-Spec Lower Parts Kit and carbine 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 Mil-Spec heavy-duty six-position 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.

SBR Ready

This Heirloom kit is configured as SBR Ready, which means it ships without a brace so the buyer can select their own final setup. The included component list above reflects exactly what ships with this kit, and it should be reviewed as supplied when planning the completed build. The lower receiver and any furniture selection remain the buyer's responsibility, separate from what's included here. The SBR Ready designation applies specifically to this configuration of the Heirloom.

Follow all manufacturer instructions and safe handling practices.

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

Lower receiver is not included.

Ships without a brace.

Do not attach a stock unless the resulting configuration complies with all applicable federal, state, and local laws.