SKU: 138482
UPC: 604206918222
MPN: 0040004BLK
The Bushmaster 0040004BLK M4 Patrolman's Upper 5.56x45mm NATO 16" Black Nitride Barrel upper receiver is purpose-built for law enforcement patrol, tactical response, and civilian AR-15 platform users who demand reliability without compromise. Designed specifically as a modular upper assembly, this component serves as the foundation for rapid rifle builds, duty weapon customization, or upgrade paths for existing AR-pattern firearms. The Patrolman designation reflects Bushmaster's heritage in serving first responders and military personnel who require combat-proven performance in field conditions.
Built on 7075-T6 aluminum construction, the receiver exhibits superior strength-to-weight characteristics critical for sustained tactical operations and extended patrol shifts. The 16-inch black nitride barrel delivers the ballistic performance of intermediate-range 5.56x45mm NATO while maintaining the handling profile required in close-quarters and vehicular environments common to law enforcement work. Black nitride finish provides corrosion resistance and a low-reflectance surface appropriate for tactical operations, while the integrated M4 handguard offers mounting flexibility for tactical accessories including lights, lasers, and vertical grips. At 5.18 pounds, this upper assembly balances firepower and maneuverability without excessive fatigue during extended carry or repeated shooting cycles.
Law enforcement agencies, military units, and AR-15 builders will find this upper receiver compatible with any mil-spec AR-15 lower receiver, enabling rapid deployment customization or duty weapon standardization. The 16-inch barrel length strikes the optimal balance between velocity retention and maneuverability in urban environments, vehicle operations, and indoor structures where excessive length compromises tactical effectiveness. Installation requires only standard receiver extension tools and familiarity with AR-platform assembly; no gunsmithing is necessary. This modular approach allows immediate integration into existing platforms or serves as the starting point for purpose-built patrol rifles tailored to specific operational requirements.
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