Upgraded Model 552 with American walnut stock, Du Pont RKW finish, pressed checkering, and higher-grade metal polish. The premium version of the 552 Speedmaster. Still in production through Roundhill Group. Type: Rifle Action: Semi-Auto Caliber: .22 LR Capacity: 15 Year introduced: 1966, USA Weight: 57 oz Overall length: 40" Status: Active Intended use: Plinking / Range Training, Collecting