Blowback-operated semi-automatic rimfire rifle chambered for .22 WMR. The HK300 predates most modern rimfire semi-autos and features HK's signature polymer furniture. Type: Rifle Action: Semi-Automatic Caliber: .22 WMR Capacity: 5 Year introduced: 1969, Germany Weight: 5.6 oz Overall length: 39" Status: Discontinued Intended use: Plinking, Small Game Hunting