Hm Upper 16" 5.56 10 3/8" Mlok Blk

The HM Defense Upper 16" 5.56 10 3/8" M-Lok Black receiver is a purpose-built upper assembly engineered for precision and reliability in demanding conditions. Built around HM Defense's proprietary MONOBLOC barrel architecture with integrally machined gas block, this upper assembly eliminates traditional pinned gas block vulnerabilities while maintaining the accuracy standards demanded by professional operators and competitive shooters. The 16-inch barrel length delivers optimal velocity from 5.56 NATO while maintaining practical handling characteristics in tactical and training environments.

The free-float rail system provides dual interface options—both Picatinny and M-Lok slots—allowing flexible accessory mounting for optics, lights, and vertical grips without rail obstruction affecting accuracy. HM Defense's patented HMB bolt replaces the standard cam pin hole with a cam pin socket and tapered cam pin design, reducing stress concentration and extending component life. The 10 3/8-inch handguard provides substantial real estate for modern optic mounts and support hand positioning while maintaining a 4.75-pound overall weight that doesn't fatigue shooters during extended range sessions or tactical training.

This upper assembly serves military units, law enforcement precision rifle teams, and serious civilian shooters pursuing accuracy-driven builds. The 5.56 NATO chambering offers proven ballistics, suppressibility, and ammunition availability. Operators integrating this upper into existing AR-15 platforms benefit from tool-less modular construction and compatibility with standard lower receivers. Black hard-coat anodize finish resists corrosion and abuse inherent to field service and training operations.

HM Defense's focus on advancing AR-15 platform reliability through engineering innovation—particularly the monolithic barrel-to-gas-block integration—addresses accuracy and maintenance concerns prevalent in duty-cycle rifles. The combination of design refinements makes this upper a competitive choice for shooters prioritizing repeatability and reduced parts count in critical systems.