Davidson Defense Overwatch 10.5-inch Pistol-Gas 1:8 .300 BLK AR-15 Freefloat Tubular M-Lok Handguard Pistol Full Build Kit, SBR Ready

Overwatch 10.5-Inch Pistol-Gas 1-8 .300 BLK AR-15 Freefloat Tubular M-LOK Handguard Pistol Full Build Kit, SBR Ready

This is an AR-15 pistol full build kit chambered in .300 AAC Blackout, centered on a 10.5-inch HBAR profile steel barrel with a Parkerized finish, a 1-8 twist rate, and a pistol-length gas system. The 7075-T6 aluminum upper receiver with a Type III hardcoat anodized finish, M4 feed ramps, a standard forward assist, and a .223 and 5.56 ejection port door with rod and spring anchors the front end. The pistol-length gas tube and micro low-profile steel gas block at .750 complete the gas system, and the 10-inch freefloat tubular aluminum M-LOK handguard with a suppressor ready profile and a 1.77-inch internal diameter covers the forend. A Steel Flash Can Design 4 in black oxide with a 5-8x24 thread pitch closes out the muzzle end. A complete AR-15 bolt carrier group made in the USA compatible with 5.56, .223, .300, and .350, and a Mil-Spec M4 charging handle complete the upper side. The lower completion package covers a complete Mil-Spec AR-15 lower parts kit with fire control group, a Mil-Spec heavy-duty 6-position buffer tube, a standard carbine buffer at 3 oz., a standard AR-15 carbine recoil spring, a Mil-Spec AR-15 M16 receiver end plate, and a Mil-Spec AR-15 carbine castle nut. This kit ships without a brace, leaving the final rear end setup to the buyer. Lower receiver not included.

Key Features

• .300 AAC Blackout chambering, 10.5-inch HBAR profile steel barrel, Parkerized finish
• 1-8 twist rate, 5-8x24 thread pitch
• Pistol-length gas system with pistol-length gas tube
• Micro low-profile steel gas block, .750
• 7075-T6 aluminum upper receiver, Type III hardcoat anodized, M4 feed ramps
• Standard AR-15 forward assist
• AR-15 .223 and 5.56 ejection port door with rod and spring
• 10-inch freefloat tubular aluminum M-LOK handguard, suppressor ready profile, 1.77-inch internal diameter
• Complete AR-15 bolt carrier group, made in the USA, 5.56, .223, .300, .350 compatible
• Mil-Spec AR-15 M4 charging handle
• Steel Flash Can Design 4, black oxide finish, 5-8x24 thread pitch
• Black 5-8-inch crush washer
• Complete Mil-Spec AR-15 lower parts kit with fire control group
• Mil-Spec heavy-duty 6-position buffer tube
• Standard carbine buffer, 3 oz.
• Standard AR-15 carbine recoil spring
• Mil-Spec AR-15 M16 receiver end plate
• Mil-Spec AR-15 carbine castle nut
• SBR Ready

Perfect For

• AR-15 pistol builders who need everything above the lower receiver for a .300 BLK build
• Shooters pairing this kit with an existing stripped or complete AR-15 lower receiver
• Builders selecting their own brace or stock for a custom .300 BLK pistol or SBR platform with a suppressor ready tubular M-LOK handguard already covered

Upper Assembly

The 7075-T6 aluminum upper receiver with a Type III hardcoat anodized finish and M4 feed ramps forms the core of the front end, with a standard forward assist and a .223 and 5.56 ejection port door with rod and spring built in. The 10.5-inch HBAR profile steel barrel brings a Parkerized finish and a 1-8 twist rate to the .300 AAC Blackout chamber, threaded at 5-8x24. The pistol-length gas tube and micro low-profile steel gas block at .750 run a pistol-length gas system along the 10.5-inch barrel. The 10-inch freefloat tubular aluminum M-LOK handguard surrounds the barrel and gas system along the forend with a suppressor ready profile featuring a 1.77-inch internal diameter that provides clearance for a compatible short suppressor mounted at the muzzle end of the barrel underneath the handguard. M-LOK slots along the handguard body provide accessory attachment across the full 10-inch length.

Bolt Carrier Group and Charging Handle

The complete AR-15 bolt carrier group is made in the USA and compatible with 5.56, .223, .300, and .350, making it a well-suited choice for this .300 BLK chambering. The Mil-Spec M4 charging handle pairs with the BCG inside the upper receiver to complete the upper interior and finish the front end of the build.

Muzzle Device

The Steel Flash Can Design 4 in black oxide threads onto the 5-8x24 muzzle end of the barrel. The included black 5-8-inch crush washer seats at the barrel shoulder and completes the muzzle hardware for this kit.

Lower Completion Components

The complete Mil-Spec AR-15 lower parts kit covers the full internal lower component group, including the fire control group, magazine catch, bolt catch, and all associated pins and springs. The Mil-Spec heavy-duty 6-position buffer tube, standard carbine buffer at 3 oz., and standard AR-15 carbine recoil spring form the buffer system at the rear of the lower. The Mil-Spec AR-15 M16 receiver end plate and Mil-Spec AR-15 carbine castle nut lock the buffer tube down cleanly at the rear of the lower receiver. The brace or stock selection is left entirely to the buyer, keeping the final rear end open for a custom setup.

SBR Ready

This kit ships without a brace and is intended for builders selecting their own final rear end setup. The Mil-Spec heavy-duty 6-position buffer tube and complete lower hardware are included, but the brace or stock is sourced separately by the buyer. The final rear end configuration is setup dependent and determined by the component the buyer selects.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Ships without a brace. Do not attach a stock unless compliant with applicable laws. Lower receiver not included.