The following years were traumatic for the regiment, and for the Australian Army, with the abolition of National Service after the end of Australian involvement in Vietnam depleting its strength to the point where training was severely restricted until it was reinforced during 1974. B Squadron was re-designated as the Medium Tank Trials Unit in 1972 and subsequently carried out extensive user and technical trials to evaluate the replacement for the ageing Centurions. In 1977 the Centurion was replaced in service by the Leopard 1, which had been selected over the American built M60 Patton. On 21 April 1981, the Colonel-in-Chief of the RAAC, The Prince of Wales, presented the unit with its first Regimental Standard. In 1995 the 1st Armoured Regiment moved from Puckapunyal to Darwin.