Bucknall was promoted to brevet lieutenant colonel on 1 January 1936, and attended the Royal Naval College, Greenwich. From 13 March 1937 until 12 April 1939 he served as an instructor at the Royal Military College of Canada, taking over from Gordon MacMillan, where he came into contact with some of the Canadian generals of the next war, such as Harry Crerar, the college Commandant, and E. L. M. Burns and Guy Simonds, both fellow instructors.
Bucknall was promoted to brevet lieutenant colonel on January 1st, 1936, and attended the Royal Naval College in Greenwich. From March 13th, 1937, until April 12th, 1939, he served as an instructor at the Royal Military College of Canada, succeeding Gordon MacMillan. During this time, he interacted with several Canadian generals who would be involved in future conflicts, including Harry Crerar (the college commandant), E. L. M. Burns, and Guy Simonds, both fellow instructors.