300 BLK Upper | 5″ 1:5 Twist Upper with Options   CM15 300 BLK Upper CM 6061 lightweight billet aluminum receiver Reliefs featured throughout the receiver Picatinny rail milled channel for a sleek/light weight option CM 6061 4″ MLOK handguard QD Sockets at 3 and 9 o’clock Full Picatinny top rail Choice of Suppressor Host Muzzle Device or Thread Protector CM15 Low Mass Bolt Carrier Group 9310 Hardened Steel Bolt 17-4 Stainless Steel Firing Pin 8620 Carrier and Key MPI Tested Hardened Extractor S7 Steel CM15 Warhammer Ambidextrous Charging Handle – in collaboration with Breek Arms Superlative Arms Adjustable Gas Block CM Melonite Gas Tube CM15 300 BLK 5″ Barrel CrMV Medium Profile Nitrided 1:5 Twist Micro Gas .750 Gas Journal 5/8×24 threaded muzzle CM15 300 BLK Upper: The Apex of Compact Power When size is the primary constraint but performance is non-negotiable, the CM15 300BLK 5″ Upper stands alone. Engineered for ultra-discreet builds and maximum maneuverability, this “micro” upper delivers hard-hitting .30 caliber authority in a package small enough for backpack carry or vehicle deployment. 1:5 Twist: Stability in a Short Format The standout feature of this build is the 1:5 ultra-fast twist rate. In such a short barrel, a standard twist often fails to stabilize heavy subsonic projectiles. Our 1:5 rifling ensures that even the heaviest 220gr bullets achieve maximum rotational stability the moment they leave the muzzle, providing pinpoint accuracy and reliable expansion where other micro-barrels fail. Optimized for the Stealth Professional Designed specifically to be the ultimate suppressor host, the 5-inch barrel length keeps your overall footprint minimal even with a “can” attached. The specialized gas port is tuned to ensure reliable cycling in the most compact configurations. Core Specs: 5” 4150 CMV Barrel: Maximum portability without sacrificing structural integrity. 1:5 Twist Rate: Specifically tuned for heavy subsonic stabilization. Customizable Options: Choose your preferred handguard, BCG, and charging handle to finish your PDW build. The CM15 5″ Upper is the definitive choice for a Personal Defense Weapon (PDW) that prioritizes stealth, speed, and stopping power. Related