Davidson Defense Atriox 16-inch Carbine-Gas 1:8 338 ARC AR-15 M-Lok Handguard Rifle Full Upper Build Kit

Atriox 16-inch Carbine-Gas 1:8 .338 ARC AR-15 M-LOK Rifle Full Build Kit

The Atriox is a .338 ARC AR-15 Full Build Kit built around a 16-inch carbine-length gas platform. The kit centers on a 16-inch HBAR profile barrel in 4150 CrMoV steel with a phosphate finish, 1:8 twist rate, and 5/8x24 thread pitch, paired with a GI birdcage flash hider at 5/8x24 and a black 5/8-inch crush washer. A micro low-profile steel gas block at 0.750 diameter and a carbine-length stainless steel gas tube are included on the front end. The 7075-T6 aluminum upper receiver carries an anodized finish with M4 feed ramps, a forward assist assembly, and an ejection port door, rod, and spring, paired with a 15-inch freefloat M-LOK handguard. A complete 6.5 Grendel Type II QPQ nitride bolt carrier group and a Mil-Spec AR-15 M4 charging handle complete the upper side. The lower hardware includes a complete Mil-Spec AR-15 lower parts kit, a Mil-Spec heavy-duty 6-position buffer tube, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, an AR-15 M16 Mil-Spec receiver end plate, and an AR-15 carbine castle nut. The SOPMOD style collapsible stock in black with storage compartments and integrated QD mounts rounds out the kit. Lower receiver not included.

Key Features

• 16-inch HBAR profile barrel, 4150 CrMoV steel, phosphate finish, 1:8 twist, 5/8x24 thread pitch, .338 ARC
• Carbine-length gas system
• Carbine-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• GI birdcage flash hider, 5/8x24, black 5/8-inch crush washer included
• 7075-T6 aluminum upper receiver, anodized, M4 feed ramps, forward assist assembly, ejection port door, rod, and spring
• 15-inch freefloat M-LOK handguard
• Complete 6.5 Grendel Type II QPQ nitride bolt carrier group
• Mil-Spec AR-15 M4 charging handle
• Complete Mil-Spec AR-15 lower parts kit
• Mil-Spec heavy-duty 6-position buffer tube
• Standard carbine buffer, 3 oz
• Standard AR-15 carbine recoil spring, made in USA
• AR-15 M16 Mil-Spec receiver end plate
• AR-15 carbine castle nut
• SOPMOD style collapsible stock, black, storage compartments, integrated QD mounts

Perfect For

• Builders sourcing a complete .338 ARC AR-15 full build kit with a 4150 CrMoV HBAR barrel, 6.5 Grendel Type II QPQ nitride BCG, SOPMOD collapsible stock with storage compartments and integrated QD mounts, and complete lower parts kit already included, pairing it with their own lower receiver
• Shooters building a 16-inch .338 ARC carbine-gas rifle platform who want the BCG, charging handle, buffer system, and SOPMOD stock covered in one kit with a GI birdcage flash hider and carbine-length stainless gas tube
• AR-15 builders who want a .338 ARC full build kit with a forward assist upper receiver, complete lower parts kit, and SOPMOD stock with integrated QD mounts without sourcing components separately

Barrel and Muzzle Device

The 16-inch HBAR profile barrel is chambered in .338 ARC and constructed from 4150 CrMoV steel with a phosphate finish. The twist rate is 1:8 and the thread pitch is 5/8x24, which matches the included GI birdcage flash hider. A black 5/8-inch crush washer, a micro low-profile steel gas block at 0.750 diameter, and a carbine-length stainless steel gas tube cover the front end gas configuration on this carbine-length platform.

Upper Receiver and Handguard

The 7075-T6 aluminum upper receiver carries an anodized finish with M4 feed ramps, a forward assist assembly, and an ejection port door, rod, and spring. The 15-inch freefloat M-LOK handguard provides M-LOK attachment points along the body for accessory mounting. These two components define the exterior structure of the upper assembly on this .338 ARC platform.

Bolt Carrier Group and Charging Handle

The complete 6.5 Grendel Type II QPQ nitride bolt carrier group is compatible with the .338 ARC platform due to the shared 6.5 Grendel bolt pattern. A Mil-Spec AR-15 M4 charging handle is included to complete the upper component set.

Lower Parts Kit and Buffer System

The complete Mil-Spec AR-15 lower parts kit covers the internal lower receiver components. The buffer system includes a Mil-Spec heavy-duty 6-position buffer tube, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, an AR-15 M16 Mil-Spec receiver end plate, and an AR-15 carbine castle nut. The SOPMOD style collapsible stock in black features storage compartments and integrated QD mounts, pairing with the included Mil-Spec buffer tube and covering the rear stock interface for this build.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included.