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

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

The Guard Dog is a Full Build Kit built around a 16-inch .338 ARC barrel with a standard profile, finished in Parkerized. It's paired with a 7075-T6 aluminum upper receiver finished in black anodizing. It pairs a 15-inch Air Lite Series M-LOK free-float handguard with a Breek Arms Plan B Echo single-port muzzle brake at the muzzle, running on a carbine-length gas system. A 6.5 Grendel II complete bolt carrier group, rated for .338 ARC, Mil-Spec charging handle, complete Lower Parts Kit, carbine buffer-system components, and an Adaptive Tactical EX Performance adjustable stock round out the rest of the rifle. The lower receiver is not included, leaving the buyer to select and supply that component separately.

Key Features

• 16-inch .338 ARC barrel, 1:8 twist, standard profile, 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 M-LOK free-float handguard, full-length monolithic Picatinny rail
• Breek Arms Plan B Echo single-port muzzle brake included
• 6.5 Grendel II complete bolt carrier group, QPQ nitride finish, .338 ARC compatible
• Adaptive Tactical EX Performance adjustable stock, model AT-02012-B
• Complete Mil-Spec Lower Parts Kit and carbine buffer-system components included
• Lower receiver is 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 and standard profile. 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 an AR-15 forward assist assembly. The ejection port carries a standard door with its rod and spring installed. 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 full-length 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.

Bolt Carrier Group and Charging Handle

A 6.5 Grendel II complete bolt carrier group is included, finished in QPQ nitride and rated for .338 ARC to match the chambering of this build. 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.

Stock

Capping off the rifle is an Adaptive Tactical EX Performance adjustable stock, model AT-02012-B, finished in black. It slides onto the six-position buffer tube included with this kit, giving the shooter adjustable length-of-pull for the final piece of the build.

Follow all manufacturer instructions and safe handling practices.

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

Lower receiver is not included.