PWS MK109 MOD1 Upper Receiver – 300 Blackout 9.75″ Barrel

Elevate your AR-15 build with the PWS MK109 MOD1 Upper Receiver in 300 Blackout, featuring a 9.75-inch barrel purpose-built for suppressed and unsuppressed short-barrel configurations. Primary Weapons Systems (PWS) is renowned for engineering some of the most reliable and precisely crafted upper receivers in the industry, and the MK109 MOD1 is no exception. Designed around PWS’s proven long-stroke piston operating system, this upper delivers consistent, reliable cycling across a wide range of 300 BLK loads — from supersonic hunting and defensive rounds to subsonic suppressor-ready ammunition. The 9.75″ barrel length strikes an ideal balance between maneuverability and ballistic performance, making it a top choice for home defense, tactical applications, and SBR/suppressor builds. Precision-machined components and tight tolerances ensure exceptional accuracy and durability, while the MOD1 configuration offers a refined feature set trusted by serious shooters and professionals alike. Whether you’re completing a custom build or upgrading an existing platform, the PWS MK109 MOD1 300 Blackout upper is a premium choice that delivers performance you can count on. Shop online at Deep Roots Rifle Co or visit our gun store in Eustis, Florida, where our knowledgeable staff can help you find the right components to complete your build. We offer competitive pricing and ship nationwide.