who plays the sergeant. in full metal jacket
R. Lee Ermey Ronald Lee Ermey (born March 24, 1944) is an American actor and voice actor, best known for his role as Gunnery Sergeant Hartman in Full Metal Jacket, which earned him a Golden Globe Award nomination for Best Supporting Actor. He is a former United States Marine Corps staff sergeant and an honorary gunnery sergeant; during his tenure in the U.S. Marine Corps, he served as a drill instructor.