Davidson Defense Atriox 18-inch Rifle-Gas 1:7.5 6MM ARC AR-15 Freefloat M-Lok Handguard Rifle Upper Build Kit

Davidson Defense Atriox AR-15 Upper Build Kit - 18-inch 6mm ARC Rifle-Gas 1:7.5 Freefloat M-Lok Handguard

The Davidson Defense Atriox is an AR-15 upper build kit chambered in 6mm ARC with an 18-inch government profile barrel. The kit includes the upper receiver, barrel, handguard, and GI birdcage flash hider. The 17-inch freefloat M-Lok handguard gives the forend a full-length, clean, accessory-ready profile. A BCG and charging handle are not included.

Key Features

• 18-inch 4150 CrMoV steel government profile barrel
• Nitride barrel finish
• 1:7.5 twist rate
• 5-in-8x24 thread pitch
• Rifle-length gas system with .750 O.D. gas block
• 7075-T6 aluminum upper receiver with M4 feed ramps, anodized finish
• 17-inch freefloat M-Lok handguard in 6061-T6 aluminum
• GI birdcage flash hider, 5-in-8x24 thread pitch

Perfect For

• AR-15 rifle builders sourcing an upper build kit in 6mm ARC
• Builders pairing an 18-inch rifle-gas upper with their own BCG and charging handle
• Shooters running a full-length freefloat M-Lok handguard configuration in 6mm ARC
• Builders completing a lightweight AR-15 upper assembly

Barrel and Gas System

The 18-inch government profile barrel is 4150 CrMoV steel with a nitride finish and a 1:7.5 twist rate optimized for the 6mm ARC caliber. The muzzle is threaded at 5-in-8x24 and pairs with the included GI birdcage flash hider. The rifle-length gas system uses a .750 O.D. gas block positioned beneath the handguard, keeping the forend profile clean and unobstructed across the full handguard length.

Upper Receiver and Handguard

The upper receiver is 7075-T6 aluminum with M4 feed ramps and an anodized finish. M4 feed ramps support reliable cartridge feeding from the magazine into the chamber. The 17-inch freefloat M-Lok handguard is 6061-T6 aluminum in black, providing a full-length clean forend with M-Lok accessory slots for bipods, lights, grips, and other attachments. The handguard extends beyond the 18-inch barrel length, with the muzzle device providing the necessary clearance past the handguard. The 6mm ARC configuration requires a 6.5 Grendel II pattern bolt carrier group, which is not included with this upper build kit.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. BCG and charging handle are not included.