Davidson Defense Sworn Oath w/SBA3 Brace 14.5-inch Mid-Gas 1:7 5.56 NATO AR-15 M-Lok Pistol Full Build Kit

Sworn Oath w/SBA3 Brace 14.5-inch 5.56 NATO AR-15 Full Build Kit

The Sworn Oath w/SBA3 Brace is built around a 14.5-inch 5.56 NATO barrel with a medium profile, finished in nitride, paired with a 7075-T6 aluminum upper receiver finished in anodizing. It pairs a 12-inch Series One M-LOK Slant-Pro handguard with an AR-15 A2 GI birdcage flash hider at the muzzle, running on a mid-length gas system. A complete bolt carrier group, Mil-Spec charging handle, complete Lower Parts Kit, carbine buffer-system components, and an SB Tactical SBA3 adjustable pistol 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, medium profile, Nitride finish
• Mid-length gas system with micro low-profile steel gas block
• 7075-T6 aluminum upper receiver, anodized finish
• Series One 12-inch M-LOK Slant-Pro handguard with front quad rail
• AR-15 A2 GI birdcage flash hider, 5.56/.223 compatible
• SB Tactical SBA3 adjustable pistol stabilizing brace included
• 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 nitride finish and medium profile. It carries a 1:7 twist rate and a 1/2x28 muzzle thread. Gas cycles back to the action through a mid-length system, running a stainless steel mid-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 machined from 7075-T6 aluminum and finished in anodizing, cut with M4 feed ramps for smooth feeding and fitted with an AR-15 forward assist assembly. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a 12-inch Series One M-LOK Slant-Pro handguard, featuring built-in QD mounts, a flat top portion, a front quad rail, anti-rotation tabs, and oblong cuts along its length.

Muzzle Device

Capping the muzzle is an AR-15 A2 GI birdcage flash hider, compatible with both 5.56 NATO and .223 Remington. It threads onto the barrel's 1/2x28 pattern and is secured in its final timed position with a 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.

Stabilizing Brace

Capping off the rear of the build is an SB Tactical SBA3 adjustable pistol stabilizing brace finished in black. It mounts to the six-position buffer tube included with this kit.

Follow all manufacturer instructions and safe handling practices.

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

Lower receiver is not included.