 In May, 1949, he led the team representing the 4th Fighter Wing at the first Air Force Worldwide Gunnery Competition at Las Vegas Air Force Base, Nevada, winning the jet portion of the competition.Garrison's noted gunnery skills and prior instructor experience resulted in his transfer in May 1950 to Las Vegas, now Nellis Air Force Base, where the USAF converted its flying training establishment into the USAF Aircraft Gunnery School.After completing the gunnery course, he remained at Nellis as an instructor and R&D officer of the 3596th Advanced Applied Tactics (later "Combat Crew Training") Squadron, where one of the instructors was Captain Manuel J. Fernandez.