Davidson Defense Grimfang SBR Ready 4.5" 300 BLK AR-15 Build Kit with Dirty .30 Suppressor

Grimfang SBR Ready 4.5-inch 1:7 300 BLK AR-15 Tubular Pistol Full Build Kit with Witt Machine The Dirty .30 Suppressor

This is a complete .300 Blackout SBR-ready pistol build kit paired with a suppressor. The 4.5-inch Bear Creek Arsenal barrel uses a 1:7 twist rate optimized for heavier subsonic and supersonic rounds. The kit includes a free-float handguard, complete bolt carrier group, charging handle, lower parts kit, buffer system, and the Witt Machine The Dirty .30 suppressor. Lower receiver not included.

Key Features

• 4.5-inch 1:7 twist barrel in 4150 Chrome Moly Vanadium Steel with Parkerized finish
• Micro-length gas system with adjustable skeletonized gas block
• 7-inch smooth free-float handguard for accurate shooting
• Complete bolt carrier group compatible with .300 Blackout, 5.56 NATO, .223 Remington, and .350 Legend
• Mil-spec lower parts kit with standard fire control group and pistol grip
• Heavy-duty carbine buffer tube, buffer, and recoil spring
• Witt Machine The Dirty .30 suppressor with 416 Stainless Steel construction and 5/8x24 threading
• SBR Ready configuration

Perfect For

• Builders creating compact .300 Blackout pistols for home defense
• Shooters wanting a complete kit with suppressor included
• Those building SBR-compliant platforms for future registration
• Subsonic ammunition users seeking integrated noise reduction
• Precision-focused builds using free-float handguard design

SBR Ready Configuration

This kit ships without a brace and is intended for builders selecting their own final setup. The SBR Ready configuration gives you flexibility to choose between a pistol brace, arm strap, or other configuration that meets your compliance requirements. The micro gas system and 4.5-inch barrel pair effectively with subsonic ammunition, making this setup ideal for suppressed shooting. Configuration choices depend on your intended use and local compliance standards.

Suppressor Integration

The Witt Machine The Dirty .30 suppressor is factory-tuned for .30 caliber platforms and threads directly onto the 5/8x24 muzzle. The 4-inch length keeps overall profile compact while reducing sound signature on both subsonic and supersonic loads. The suppressor uses 416 Stainless Steel with Graphite Black Cerakote for durability. This pairing optimizes the short-barrel platform for hearing-safe operation.

Complete Kit Components

This full build kit includes the upper assembly with barrel, handguard, and all operating components, plus the complete lower parts kit, buffer tube, buffer, recoil spring, end plate, and castle nut. The bolt carrier group is USA-manufactured and fully compatible with .300 Blackout ammunition. All you need to complete the build is a serialized lower receiver.

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. Verify suppressor compatibility before use. Ensure secure mounting before operation. Use only in accordance with applicable laws. May Dropship from Davidson Defense.