The Primary Weapons Systems MK1-M1U-300BLK9 MK109 Mod 1-M Upper Receiver brings PWS’s proven long stroke piston system to a compact 9.75" 300 Blackout platform. Built on a forged AR-15 upper with a free-float PicLok MLOK handguard and Triad 30 muzzle device, it is engineered for clean, reliable cycling with both super and subsonic 300 BLK ammunition, including suppressed setups.
This complete upper is ideal for building a short, smooth-shooting AR-15 for range use, training, or dedicated suppressor work where reduced fouling and adjustable gas are priorities. The combination of precision Boise-made barrel, adjustable gas system, and ambidextrous Radian Raptor charging handle supports confident handling and consistent accuracy. It reflects Primary Weapons Systems’ focus on thoughtful engineering and durable, shooter-focused design.
- Manufacturer: Primary Weapons Systems
- Model: MK109 Mod 1-M
- Caliber: 300 AAC Blackout
- Barrel Length: 9.75"
- Rate Of Twist: 1:8
- Muzzle Device: PWS Triad 30
- Handguard Type: PicLok MLOK Free-Float
- Receiver Style: Complete Upper Receiver
- Gas System: PWS Long Stroke Piston With 3-Setting Adjustable Gas Block
- Charging Handle: Radian Raptor Ambidextrous
| __Capacity | NA |
| __Barrel Length | NA |
| __Optic Footprint | NA |
| __Action | NA |
| __Caliber | .300 Blackout |
| __Model | MK109 MOD 1-M |
