The Primary Weapons Systems Mk1 Mod 2-m Upper in 300 Blackout delivers a compact, ready-to-fire solution for AR-style builds, blending a complete upper receiver with precision engineering and purpose-driven features. Built around a 9.75-inch barrel and a lightweight forged profile, this upper integrates the MK109 MOD 2-M design with a Frc Comp muzzle device to help manage recoil and muzzle rise for swift follow-up shots. The 300 AAC/Blackout chamber is optimized for subsonic and supersonic loads alike, unlocking versatile performance for close-quarters engagements, varmint control, or suppressor-compatible configurations. The Mod 2-M architecture emphasizes reliability and compatibility, ensuring a tight, repeatable fit with standard AR-compatible components while maintaining optimal gas system timing for smooth cycling. With a focus on practical field use, the upper receiver assembly provides robust durability, efficient heat management, and a streamlined platform for rapid assembly or upgrade of a dedicated rifle build. Whether refining a hunting rifle, duty-ready setup, or precision range rig, this PWS upper delivers consistent performance, straightforward maintenance, and the versatility to adapt to a wide range of shooting scenarios.