Stern Defense 9mm Luger 4" Barrel M-LOK Mod 4 Pistol Upper

The Stern Defense 9mm Pistol Upper is a complete upper receiver assembly built for compact AR-15 pistol platforms chambered in 9mm Luger. The assembly pairs a short 4" steel barrel finished in Melonite with a slim, matching 4" Mod 4 M-LOK handguard, delivering a lightweight and maneuverable package for pistol-caliber AR builds.

The Mod 4 M-LOK handguard provides a clean, uncluttered look while accepting any M-LOK-compatible accessory - lights, lasers, vertical grips, or rail sections. The Melonite-treated steel barrel offers excellent wear and corrosion resistance for high-round-count 9mm use. As a complete upper, this assembly ships with the bolt included and is ready to drop onto a 9mm-compatible AR-15 pistol lower receiver (lower sold separately), making it an easy way to add or complete a 9mm AR pistol build.

This Stern Defense pistol upper is a compact foundation for a 9mm AR pistol, offering a short overall footprint, modular M-LOK accessory support, and the reliability needed for range or defensive use.