Windham's SRT8-4A pistol in .300 Blackout with an 8-inch barrel — purpose-optimized for suppressor use with subsonic .300 BLK loads. The 8-inch barrel provides adequate dwell time for reliable cycling with both supersonic and subsonic .300 BLK ammunition when suppressed. Type: Pistol Action: Semi-Automatic Caliber: .300 BLK Capacity: 30 Year introduced: 2015, United States Weight: 72 oz Overall length: 19.5" Status: Active Intended use: Recreational Shooting, Home Defense