LUXUS ARMS HM Defense MonoBloc Upper .223 REM 16″ 15″ M-LOK

The HM Defense 16MBUP556L MonoBloc Upper from LUXUS ARMS (HM DEFENSE) is a complete AR-15 upper assembly built for use in .223 REM / 5.56x45mm NATO platforms. It incorporates a 16″ 4150 Chrome Moly match-grade barrel with an integral machined patented gas block and a carbine gas system for reliable cycling. The free-floating 15″ M-LOK handguard includes a long Picatinny top rail for optics and accessory placement. The upper uses 7075-T6 aluminum receivers with a hard coat anodized finish and ships with the HMB bolt, mil-spec components, charging handle, and a dust cover bearing an American flag.

Key Specifications

• The caliber is .223 REM/5.56 NATO.
• The barrel length is 16″.
• The barrel material is 4150 Chrome Moly.
• The barrel finish is Black Cerakote.
• The barrel is described as 4150 Chrome Moly Match Grade with tripled-honed, button-rifled construction.
• The rate of twist is 1:8″.
• The handguard is a 15″ M-LOK Free-Float design with an extended Picatinny top rail.
• The handguard finish is Black Hard Coat Anodized.
• The receiver material is 7075-T6 Aluminum with a Black Anodized finish.
• The upper uses a carbine gas system and includes the patented HMB bolt and mil-spec components.

With match-grade barrel work, a long M-LOK free-float handguard, and durable 7075-T6 construction, this MonoBloc upper is specified for shooters who value verified components and dependable function. Its combination of features supports a broad range of AR-15 uses including range training and general-purpose shooting, while providing a modern mounting platform for optics and accessories.