Adams Arms P3 piston-driven AR-15 in 6.8 SPC with 16-inch barrel, using a short-stroke push-rod piston system for cooler and cleaner operation. Type: Rifle Action: Semi-Automatic Caliber: 6.8 SPC Capacity: 26 Year introduced: 2015, USA Weight: 96 oz Overall length: 32.5" Status: Active Intended use: Tactical, Hunting