Stern Defense SD15 Mod4 9mm Luger 16.1" 15" M-LOK Complete Upper - Black

The Stern Defense SD15 Mod4 is a complete 9mm Luger AR-15 upper receiver assembly built around a 16.1" barrel finished in Black Melonite with a 1:10 twist rate. The upper receiver is machined from 6061 aircraft-grade aluminum and finished in hard-coat anodized black for lasting durability and corrosion resistance.

This upper ships fully assembled from the factory with a standard dust cover and forward assist, a 15" MOD4 M-LOK handguard secured by a clamp-on mounting system, and a Glock-pattern magazine cut on the upper. The included Glock-cut bolt is purpose-built for reliable feeding with 9mm pistol-caliber magazines.

Designed and assembled in the USA, the SD15 Mod4 drops onto any mil-spec AR-15 lower receiver, giving shooters a turnkey pistol-caliber carbine (PCC) build chambered in 9mm Luger with a modern M-LOK interface for accessories.