Primary Weapons M116UA0B MK1 Mod 1-M Upper 223 Wylde 16.10" Chrome-Lined 4140 Steel Barrel w/Removeable Muzzle Device, 7075-T6 Anodized Aluminum Receiver, 15.05" M-LOK Handguard For AR-15

The Primary Weapons M116UA0B MK1 Mod 1-M Upper 223 Wylde 16.10" Chrome-Lined 4140 Steel Barrel with removable muzzle device is purpose-built for shooters demanding a precision-engineered, combat-ready AR-15 upper receiver. Whether you're an LEO upgrading duty rifle accuracy, a military armorer standardizing platform performance, or a civilian marksman prioritizing consistency, this upper assembly delivers repeatable performance across diverse ammunition loads. The 223 Wylde chamber tolerances accommodate both 5.56 NATO and .223 Remington cartridges without sacrificing headspace integrity—a critical advantage in field operations where ammunition availability varies.

Built on a 7075-T6 anodized aluminum receiver, this upper provides the durability and dimensional stability required for sustained accuracy under duty cycles. The 4140 chrome-lined barrel resists corrosion and extends throat life in high-round-count environments—chrome lining adds measurable service life compared to unlined barrels, particularly in humid or salt-air conditions. At 16.10 inches, the barrel length balances velocity retention with maneuverability in CQB or vehicle-confined scenarios. The 15.05" M-LOK handguard offers abundant mounting space for lights, lasers, and optics while remaining free-float compatible for accuracy optimization. The removable muzzle device allows users to swap suppressors, compensators, or flash hiders based on mission requirements without permanent installation.

This upper is designed for immediate integration with standard AR-15 lower receivers—no special tools or smithing required for assembly. Law enforcement agencies, military units, and serious civilian shooters benefit most from the chambering flexibility and modular design. At 5.17 lbs, the upper contributes manageable overall rifle weight, making it suitable for long-duration patrol or training. Pair this with quality optics and match-grade ammunition to unlock the inherent 223 Wylde accuracy potential. All components are finished to military specifications and tested for reliability in field conditions.