Davidson Defense Atriox 16-inch Carbine-Gas 1:8 5.56 NATO AR-15 M-Lok Rifle Complete Upper Build

Atriox 16.25-inch 5.56 NATO AR-15 Complete Upper

The Atriox is built around a 16.25-inch 5.56 NATO barrel with an M4 profile, finished in nitride, paired with a 7075-T6 aluminum upper receiver finished in anodizing. It pairs a 15-inch Series A M-LOK Slant-Pro handguard with an AR-15 A2 GI birdcage flash hider at the muzzle, running on a carbine-length gas system. A complete bolt carrier group and Mil-Spec charging handle round out the upper, giving the buyer everything needed on the upper side.

Key Features

• 16.25-inch 5.56 NATO barrel, 1:8 twist, M4 profile, Nitride finish
• Carbine-length gas system with micro low-profile steel gas block
• 7075-T6 aluminum upper receiver, anodized finish
• Series A M-LOK Slant-Pro 15-inch handguard with front quad rail
• AR-15 A2 GI birdcage flash hider, 5.56/.223 compatible
• Complete bolt carrier group and Mil-Spec charging handle included

Barrel and Gas System

The barrel runs 16.25 inches long, chambered in 5.56 NATO and built from 4150 chrome moly vanadium steel with a nitride finish and M4 profile. It carries a 1:8 twist rate and a 1/2x28 muzzle thread. Gas cycles back to the action through a carbine-length system, running a stainless steel carbine-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 15-inch Series A M-LOK Slant-Pro handguard, featuring built-in QD mounts, a flat top, 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 upper remain 5.56 NATO. A Mil-Spec AR-15 M4 charging handle rounds out the upper's operating components.

Follow all manufacturer instructions and safe handling practices.

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