After the experiences of improvised tank destroyer vehicles such as the M3 half-track with 75mm gun, M6 truck with 37mm gun and the M10 tank destroyer (3-inch gun on a modified M4 Sherman hull), the US Army were keen to produce a bespoke tank destroyer to hunt enemy armour. An order was issued in late 1941 to mount a 37mm gun in the requested vehicle. This was to be upgraded several times to 57mm, 75mm and then finally a 76mm. The result of this development would be the M18 Hellcat - the fastest US armoured fighting vehicle of the Second World War. M18 Hellcats served in the invasion of the Phillipines and saw action in Europe during the landings at Anzio in Italy and in Northwest Europe. Hellcats were also exported to China where they served in an infantry support role. The Hellcat could be found in the service of several nations following World War II with the Yugoslav army still fielding them into the 1990s!