55 S 55

55 S 55 (from Finnish 55 millimetrin sinko vuodelta 1955, '55 millimetre recoilless anti-tank weapon model 1955'), colloquially kevyt sinko and nicknamed Nyrkki, was a Finnish recoilless anti-tank weapon from the mid-1950s. The 55 S 55 was designed by a Finnish Defence Forces team led by MSc, Capt Esko Puronto, and it was manufactured by FDF's Vammaskoski factory (now part of Finnish state military industrial enterprise Patria).