During the Hungarian Revolution of 1956, a Soviet T-54A medium tank was driven onto the grounds of the UK's embassy in Budapest by the Hungarians. After a brief examination of this tank's armor and 100 mm gun by a British military attaché, the UK decided that their 20 pounder (84mm L/66.7) was apparently incapable of defeating it. There were also rumors of an even larger 115 mm gun in the works. In response to this the US Army started development of the XM60 to replace the M48 tank series and incorporating the ARCOVE recommendation of a more powerful main gun, the 105mm T254. Instead of immediately getting a 105mm main gun, the M48A3 tanks were to retain their existing M41 90mm main guns due to funding shortfalls that made it impossible to supply enough 105mm main gun rounds for all the planned converted tanks. Secondly, there were still large stockpiles of 90 mm main gun rounds on hand.