The HM Defense 16MBUP-556 MonoBloc Upper is a distinctive piece that incorporates a HM barrel with a unique, patented gas block integrated into a carbine gas system. Crafted from 4150 Chromoly, this match-grade feature touts triple honing and button rifling for absolute precision.Accompanying the barrel is a free-floating handguard equipped with a Picatinny rail and Magpul M-LOK. This handguard is machined from robust 6061-T6 aluminum for durability and reliability.The Upper and Lower receiver are constructed from high-strength 7075-T6 aluminum and finished with a protective hard coat anodizing to strengthen and safeguard against wear and tear. To complete the package, the MonoBloc Upper includes a patented HMB bolt, Mil-Spec components, a charging handle and a dust cover embellished with an American Flag for a patriotic touch.