During the 1960"s, the Israeli Ordnance Corps upgraded their aging Sherman Tanks by equipping it with the powerful French 105mm CN-105-F1 tank gun. The gun barrel length was shortened by 1.5m to improve overall greater balance and a muzzle brake was also fitted to minimize the recoil effect. In 1967, during the Six-Day War, the Super Sherman found itself fighting against newer T-54/55 tanks as well as JS-3 tanks from Egyptian, Iraqi, and Syrian armies. The M-51"s 105mm gun could take on these adversaries by using HEAT ammunition. After the war, these M-51 Super Shermans continued to serve with distinction until they were finally retired in the early 1980s.