Davidson Defense Dwarf King AR-15 4.5" 300 BLK Pistol Upper Build Kit with Witt Machine Dirty .30

Dwarf King 4.5-inch 1:7 300 BLK AR-15 M-LOK Pistol Upper Build Kit with Witt Machine Suppressor

This is a complete 300 Blackout pistol upper built around a 4.5-inch barrel with a Witt Machine The Dirty .30 suppressor already mounted. The setup includes a freefloat M-LOK handguard, adjustable gas block, and everything needed to run subsonic or supersonic ammunition in a compact platform. BCG and charging handle are not included.

Key Features

• Bear Creek Arsenal 4.5-inch barrel, 1:7 twist, 4150 chrome moly vanadium steel with parkerized finish
• Panhead billet upper receiver with .458-size ejection port and included ejection port door assembly
• 7-inch freefloat M-LOK aluminum handguard, suppressor-ready design with 1.77-inch internal diameter
• Adjustable skeletonized gas block tuned for micro-length gas system
• Witt Machine The Dirty .30 compact suppressor, 416 stainless steel with graphite black cerakote, 4 inches long
• Suppressor pre-mounted and ready to use

Perfect For

• Shooters building compact 300 BLK pistol platforms with integrated sound suppression
• Home defense builds prioritizing concealability and hearing protection
• Suppressed 300 BLK subsonic shooting without additional muzzle device purchases
• Builders wanting a complete upper assembly minus lower receiver components

Suppressor-Ready Compact Platform

This upper is purpose-built around suppressed 300 Blackout performance. The Witt Machine suppressor comes pre-mounted on the 5/8x24 threaded barrel, eliminating the need to source and attach a muzzle device separately. The 7-inch M-LOK handguard provides mounting space for accessories while maintaining a compact overall footprint ideal for pistol configurations. The adjustable gas block allows tuning for both subsonic and supersonic loads, which is critical when running a suppressor on a short-barrel platform.

Micro-Length Gas System Design

The micro-length gas tube and adjustable gas block are sized specifically for 4.5-inch barrel cycling. This configuration reduces felt recoil and improves reliability when shooting through a suppressor, where back-pressure increases. The adjustable block lets you fine-tune gas flow based on ammunition type and suppressor use, preventing short-stroking on subsonic rounds or over-gassing on hotter loads.

300 Blackout Barrel Specifications

The 1:7 twist rate stabilizes both 110-grain and 220-grain projectiles effectively, making this upper flexible for subsonic and supersonic ammunition. The 4150 chrome moly vanadium steel barrel is parkerized for corrosion resistance. Barrel length of 4.5 inches keeps velocity suitable for suppressed shooting while maintaining the compact form factor. The HBAR profile provides rigidity and heat capacity for sustained fire without excessive barrel whip.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Verify suppressor compatibility before use. Ensure secure mounting before operation. Use only in accordance with applicable laws. May Dropship from Davidson Defense.