Davidson Defense 'More Perfect Union' 16.5" AR-15 5.56 NATO Nitride Rifle Complete Upper Build Kit

Davidson Defense 'More Perfect Union' 16.5" AR-15 5.56 NATO Nitride Rifle Complete Upper Build Kit

The Davidson Defense 'More Perfect Union' is a complete upper build kit built around a 4150 CrMoV nitride barrel paired with a free-float handguard, USA-made 9310 alloy bolt carrier group, and mid-length gas system. This is a fully assembled upper ready to pair with your lower receiver.

Key Features

• 16.5-inch 4150 CrMoV nitride barrel with 1:7 twist rate for reliable 5.56 NATO cycling
• Free-float 15-inch aluminum handguard eliminates barrel contact for consistent accuracy
• USA-made 9310 alloy bolt carrier group with nitride finish for durability
• Billet aluminum upper receiver with Type III hard coat anodize
• Mid-length stainless steel gas tube with micro low-profile gas block
• AR-15 M4 charging handle and GI-pattern A2 flash hider included
• 1/2x28 thread pitch compatible with standard suppressors and muzzle devices

Perfect For

• Builders looking for a complete upper assembly without sourcing individual components
• Shooters who want quality USA-made internals with proven barrel steel
• Mid-range builds balancing accuracy, reliability, and cost-effectiveness
• Precision shooters benefiting from free-float handguard consistency

Nitride Barrel Performance

The 4150 CrMoV barrel with nitride finish provides a balance between durability and corrosion resistance. Nitride treatments harden the barrel surface while maintaining the material's core toughness, making this barrel suitable for high-round-count shooting without excessive wear. The 1:7 twist rate stabilizes a wide range of 5.56 ammunition, from lighter 55-grain rounds to heavier 77-grain loads.

Mid-Length Gas System Design

This upper uses a mid-length gas tube, which positions the gas port between rifle-length and carbine-length systems. Mid-length systems typically deliver softer recoil impulses compared to carbine-length tubes while maintaining reliable cycling across various ammunition types and suppressor configurations.

Free-Float Handguard Advantage

The 15-inch free-float handguard eliminates contact between the handguard and barrel, removing a common source of accuracy inconsistency. Free-float designs allow the barrel to vibrate naturally without external interference, which can improve shot-to-shot consistency at distance.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included.