Education
McMillan attended Turtle Creek High School in Pennsylvania.
McMillan attended Turtle Creek High School in Pennsylvania.
Between 1952 and 1976 he competed in the 25 m rapid fire pistol event in six Olympics, missing only the 1956 Games due to malfunctioning of his weapon during the United States trials. In his career, he set two world shooting records. In 1994, United States of America Shooting inducted him into the United States of America Shooting Hall of Fame.
McMillan enlisted in the Marine Corps in 1946.
He was commissioned a 2nd Lieutenant in 1953 and retired as a Lieutenant Colonel in 1974. He served in the Korean and Vietnam wars.
From 1974–1981, he worked as a Weapons Training Coordinator at San Diego County, California. where he was injured in a shooting accident at the old Camp Elliot range. In 1978, the Marine Corps established the McMillan Trophy for shooting in his honor.