Davidson Defense Grimfang 4.5" 300 BLK AR-15 Full Build Kit, Gauntlet Arms Brace & Dirty .30 Suppressor

Grimfang w/Gauntlet Arms Brace 4.5-inch 1:7 300 BLK AR-15 Tubular Pistol Full Build Kit

This is a complete .300 Blackout AR-15 pistol kit with everything except the lower receiver. You get a 4.5-inch Bear Creek Arsenal barrel, 7075-T6 upper receiver, free-float handguard, adjustable gas block, and the Witt Machine Dirty .30 suppressor included. The kit ships with a Gauntlet Arms stabilizing brace, complete bolt carrier group, charging handle, lower parts kit, and all buffer system components. Lower receiver not included.

Key Features

• 4.5-inch Bear Creek Arsenal barrel in 1:7 twist rate, optimized for .300 Blackout subsonic and supersonic loads
• 7075-T6 aluminum upper receiver with anodized finish and complete forward assist and ejection port assembly
• Free-float 7-inch smooth handguard for consistent accuracy and rail-free design
• Adjustable skeletonized gas block with .750-inch journal for tuning blowback cycling
• Witt Machine Dirty .30 suppressor in 416 stainless steel with graphite black Cerakote finish
• Complete AR-15 bolt carrier group compatible with .300 Blackout, .223 Remington, 5.56 NATO, and .350 Legend
• Mil-spec lower parts kit with standard fire control group and pistol grip
• Heavy-duty pistol buffer tube with standard 3-ounce carbine buffer and recoil spring
• Gauntlet Arms polymer stabilizing brace in black

Perfect For

• Shooters building a compact .300 Blackout pistol with integrated suppression
• Home defense builds prioritizing subsonic ammunition compatibility
• Shooters wanting a complete kit without sourcing individual components
• Suppressed shooting without the complexity of separate suppressor purchases

Adjustable Gas Block Tuning

The adjustable skeletonized gas block allows you to dial in the gas system for optimal cycling with both subsonic and supersonic .300 Blackout ammunition. This is especially useful because .300 Blackout loads vary significantly in pressure and velocity. You can fine-tune the system to reduce felt recoil and improve reliability depending on your ammunition choice, which matters when running a suppressor that adds back pressure to the system.

Witt Machine Dirty .30 Suppressor Integration

The Witt Machine Dirty .30 comes pre-installed and ready to use. It measures 4 inches long and uses 416 stainless steel construction with graphite black Cerakote finish. The suppressor threads directly onto the 5/8x24 muzzle thread, and the included design handles the pressure curve of .300 Blackout effectively. This eliminates the need to purchase a suppressor separately and ensures compatibility out of the box.

Barrel and Twist Rate Specifications

The 4.5-inch Bear Creek Arsenal barrel features a 1:7 twist rate, which is ideal for stabilizing heavier .300 Blackout projectiles, particularly the subsonic rounds commonly used with suppressors. The barrel uses 4150 chrome moly vanadium steel with parkerized finish, and the HBAR profile provides consistent accuracy without excessive weight. The micro-length gas system keeps the overall profile compact while maintaining reliable cycling.

May Dropship from Davidson Defense.

Verify suppressor compatibility before use. Ensure secure mounting before operation. Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws.