In the Caucasus the Russians found the lighter T-62 with its manual gearbox, lighter weight, non-turbocharged diesel engine and larger ammunition supply of various types with four crewmen was better that the T-72 or T-80. The Centurion tank used by the Australian Army in Vietnam with its 20pdr/84mm gun was just as successful as the Leopard C1 with the 105mm gun in Afghanistan. A powerful medium calibre gun, with varied ammuniton types is ideal in a COIN environment.