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

Guard Dog 16-inch .338 ARC AR-15 Upper Build Kit

The Guard Dog is built around a 16-inch .338 ARC barrel finished in Parkerized, paired with a 7075-T6 aluminum upper receiver finished in black anodizing. It pairs a 15-inch Air Lite Series free-float M-LOK handguard with a Breek Arms Plan B Echo single-port muzzle brake, running on a carbine-length gas system. BCG and charging handle are not included, leaving the buyer to supply those components separately.

Key Features

• 16-inch .338 ARC barrel, 1:8 twist, Parkerized finish
• Carbine-length gas system with micro low-profile steel gas block
• 7075-T6 aluminum upper receiver, black anodized finish
• Air Lite Series 15-inch free-float M-LOK handguard, monolithic Picatinny rail
• Breek Arms Plan B Echo single-port muzzle brake included
• BCG and charging handle are not included.

Barrel and Gas System

The barrel runs 16 inches long, chambered in .338 ARC and built from 4150 chrome moly vanadium steel with a Parkerized finish. It carries a 1:8 twist rate and a 5/8x24 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 black anodizing, cut with M4 feed ramps for smooth feeding and fitted with a forward assist. The ejection port door is included with its rod and spring. Over the barrel sits a 15-inch Air Lite Series handguard, free-floated and finished in black, using an M-LOK attachment system with a monolithic Picatinny rail running along its top.

Muzzle Device

Capping the muzzle is a Breek Arms Plan B Echo single-port muzzle brake, threaded to match the barrel's 5/8x24 pattern. This muzzle device is built around the Plan B mounting ecosystem, giving the buyer that modular mounting interface at the muzzle.

Follow all manufacturer instructions and safe handling practices.

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