Davidson Defense Aegis Lightweight 10.5-inch Pistol-Gas 1:8 .338 ARC AR-15 Freefloat M-Lok Handguard Pistol Upper Build Kit

Aegis Lightweight 10.5-inch Pistol-Gas .338 ARC AR-15 Freefloat M-Lok Handguard Pistol Upper Build Kit

This is a complete AR-15 pistol upper build kit in .338 ARC, built around a 10.5-inch 4150 CrMoV barrel with a 1:8 twist rate and lightweight freefloat M-Lok handguard. The upper receiver is 7075-T6 aluminum with M4 feed ramps, and the kit includes a low-profile gas block, pistol-length gas tube, forward assist assembly, ejection port door, and a GI birdcage flash hider. This configuration delivers compact handling for .338 ARC in a pistol-length platform without sacrificing barrel rigidity or precision potential.

Key Features

• 10.5-inch 4150 CrMoV barrel with 1:8 twist rate optimized for .338 ARC ammunition
• Freefloat M-Lok handguard reduces barrel harmonics for improved accuracy
• Low-profile gas block with pistol-length gas tube for compact cycling
• 7075-T6 aluminum upper receiver with M4 feed ramps and anodized finish
• GI birdcage flash hider with crush washer included
• Forward assist assembly and ejection port door included

Perfect For

• Shooters building compact .338 ARC AR-15 pistol platforms
• Builders seeking a complete upper assembly without BCG and charging handle
• Those prioritizing lightweight construction with freefloat accuracy benefits
• Pistol-length gas system builds in intermediate calibers

.338 ARC Platform Advantages

The .338 ARC round offers ballistic performance between 5.56 NATO and .308 Winchester, making it well-suited for AR-15 platforms. This 10.5-inch configuration maintains velocity and energy in a compact form factor while the 1:8 twist rate stabilizes heavier .338 ARC projectiles effectively. The freefloat handguard design isolates the barrel from external pressure, reducing shot-to-shot harmonics and supporting precision shooting at distance.

Freefloat Handguard Design

Freefloat handguards separate the barrel from the upper receiver and handguard structure, allowing the barrel to vibrate naturally without external dampening. This design reduces inconsistent pressure points that can shift point of impact between shots. The M-Lok mounting system provides modular accessory compatibility while keeping the handguard lightweight and rigid.

Compact Pistol-Gas Configuration

The pistol-length gas system cycles faster than rifle-length tubes, returning the bolt carrier group with increased velocity. This compact design suits shorter barrels and reduces felt recoil impulse. The low-profile gas block integrates cleanly without adding bulk to the upper assembly, maintaining the lightweight profile throughout the build.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. BCG and charging handle are not included.