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

Shortshot 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 upper receiver assembly built for compact pistol platforms. It pairs a 4.5-inch barrel with a 7-inch free-float M-LOK handguard and includes an adjustable gas block tuned for subsonic and supersonic ammunition. The package comes with The Dirty .30 suppressor from Witt Machine, a direct-thread 4-inch .30 caliber unit finished in graphite black Cerakote. This upper is designed to integrate with standard AR-15 lower receivers and delivers the ballistic efficiency of 300 BLK in a short-barreled platform.

Key Features

• Bear Creek Arsenal 4.5-inch 300 BLK barrel with 1:7 twist rate and micro length gas system
• Free-float M-LOK handguard with 1.77-inch internal diameter for optic and accessory mounting
• Adjustable skeletonized gas block for ammunition tuning across subsonic and supersonic loads
• Witt Machine The Dirty .30 suppressor included, direct-thread 5/8x24, 416 stainless steel construction
• 7075-T6 aluminum upper receiver with M4 feed ramps and forward assist assembly

Perfect For

• 300 BLK pistol builds requiring compact upper assemblies
• Shooters prioritizing suppressed performance with factory-matched components
• Platforms where barrel length and overall size matter for maneuverability
• Ammunition flexibility across subsonic and supersonic loadings

Suppressor-Ready Compact Design

The 7-inch M-LOK handguard is engineered for suppressor-ready applications, accommodating the included Witt Machine unit without interference. The micro length gas system and adjustable gas block work together to cycle both subsonic and supersonic 300 BLK ammunition reliably. The 4-inch suppressor length keeps overall profile compact while delivering effective sound reduction. This configuration eliminates the need to source matching components separately.

Ballistic Platform and Caliber Efficiency

The 1:7 twist rate stabilizes both heavy subsonic rounds and standard supersonic loads, making this upper flexible for different mission profiles. The 4.5-inch barrel length balances velocity retention with compact handling in 300 BLK, where shorter barrels remain effective compared to larger calibers. The micro length gas system is optimized for this barrel length, ensuring consistent cycling and reliability across ammunition types.

Included Components and Compatibility

This upper build kit includes the upper receiver, barrel, handguard, gas tube, and gas block. The Witt Machine suppressor is included and threads directly onto the barrel. BCG and charging handle are not included. This assembly fits standard AR-15 lower receivers with mil-spec dimensions.

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. BCG and charging handle are not included. May Dropship from Davidson Defense.