Stern Defense SD8 Mod5 M-LOK 45 ACP 6" AR-15 Upper

The Stern Defense SD8 Mod5 M-LOK is a compact 45 ACP complete upper assembly for the AR-15 platform, purpose-built for short pistol-caliber builds where a stubby, maneuverable package is the priority. The upper pairs a stubby barrel with a free-float M-LOK handguard so you get a clean, modern mounting surface for optics, lights, and slings without giving up the inherent pointability of a 6" barrel setup.

At the core is a 6" barrel machined from Chrome Moly Steel with a 1:16" rate of twist and finished in Black Melonite for excellent corrosion and wear resistance in a hard-use pistol-caliber carbine. The Melonite treatment also gives the barrel a deep, uniform black finish that matches the rest of the assembly.

The upper receiver is a Mil-Spec flat top machined from 7075-T6 aluminum and hard-coat anodized for long-term durability. Stern Defense finishes it off with their laser-engraved dust cover and forward assist for a clean, factory-built appearance right out of the box.

Up front, the 8" MOD5 M-LOK free-float handguard is machined from 6061 aircraft grade aluminum and hard-coat anodized to match the receiver. M-LOK slots run along the handguard for accessories, and integrated quick-detach swivel holes accept standard QD sling mounts directly without adapters.

Drop this Stern Defense upper onto any standard AR-15 lower to field a dedicated 45 ACP pistol-caliber carbine or pistol platform with a compact, maneuverable footprint.