The Aero Precision M4E1 in .224 Valkyrie pairs Aero's enhanced receiver with the high-velocity long-range cartridge developed by Federal Premium. The 18-inch stainless barrel maximizes the Valkyrie's velocity and long-range accuracy potential. The M4E1 enhanced lower with adjustable gas block provides the best foundation for the demanding .224 Valkyrie cartridge. Type: Rifle Action: Semi-Automatic Caliber: .224 Valkyrie Capacity: 30 Year introduced: 2018, USA Weight: 70 oz Overall length: 36.5" Status: Active Intended use: Long-Range Shooting, Varmint Hunting, Precision Rifle, Long-Range, Precision, Competition