Lieutenant Colonel William J. Barnard, CD enlisted in 50^th Field Regiment as a Gunner Recruit and trained in the Summer Militia Training Program in 1964. On completion of summer training he transferred to the Militia as a Gunner in 149 Battery. In the summer of 1965 he successfully completed the Central Area Jr NCO course at Niagara on the lake, and was  promoted to Bombardier that year. In the summer of 1966 he successfully completed  the Central Area Sr NCO course at Niagara on the Lake and was  promoted to Sergeant that year. In February 1967 Barnard took a voluntary release from the Militia.

In 1968 he applied for a commission and was commissioned as Second Lieutenant in the 50^th Field Regiment in November 1968. Due to a reorganization of the Militia, he remustered from Artillery to Infantry and was a platoon Commander in B Company Hastings & Prince Edward Regiment from 1969 to 1971. In 1970 he successfully completed the Combat Team Commander’s course in Petawawa.

After completion of his studies, Barnard moved to Toronto to begin a career with the Department of National Revenue. He transferred to the Queen’s Own Rifles that year and was variously a Platoon Commander, Training Officer and Adjutant. He was promoted to Captain in 1973, and that year he and Cpl Stelmach took part in Exercise New Viking that was conducted at Resolute Bay and Mould Bay in the Arctic. In 1974 he took part in the Regiment’s participation in the “D Plus 30” celebrations in Britain and France along with the Commanding Officer, the Honorary Colonels, the Bugle Band and a number of D-Day veterans. Barnard successfully completed the Major Qualifying Course in Nanaimo, BC in 1975. He was appointed as Company Commander 60^th  Company in 1976.

Barnard was posted to Central Militia Area (CMA) Headquarters in 1978 as an SO3 OPS and was promoted to Major in 1979 while at CMA. In 1979 Barnard was posted back to the Regiment to assume the duties of Deputy Commanding Officer from 1979 to 1981. In 1980 he, along with the Honorary Colonels and the RSM formed a contingent to represent the Regiment in the annual Lord Mayor’s Parade in London England. Upon the unexpected death of Lieutenant Colonel W.S. Wilson, Barnard was promoted to Lieutenant Colonel and appointed Commanding Officer from January 1981 until April 1984. In 1982 the Regiment received an Operational Tasking to initially provide a Platoon of trained jumpers to the Canadian Airborne Regiment. In 1983 LCol Barnard completed the Basic Parachutist Course at CFB Edmonton. He was chosen to command a battalion of 560 all ranks formed from the Infantry units of Toronto, Hamilton and London Districts in Exercise Rampant Beaver in the summer of 1982.

LCol Barnard relinquished command of the Regiment in Apr of 1984 and in 1986 assumed the duties of SSO ADM at Central Militia Area. In 1986 he transferred to the Militia Officer Training School and was an instructor and later Course Commander for the Militia Command and Staff Course until being posted to the Supplementary List in 1994.