(shamelessly lifted from IMDB)
Former US Marine Corps Drill Instructor R. Lee Ermey was not originally hired to play Gunnery Sgt. Hartman but as a consultant for the Marine Corps boot camp portion of the film. He performed a demonstration on videotape in which he yelled obscene insults and abuse for 15 minutes without stopping, repeating himself or even flinching – despite being continuously pelted with tennis balls and oranges. Stanley Kubrick was so impressed that he cast Ermey as Hartman.
He is of course also the voice of the army men sergeant in Toy Story. 😀
Also, the highest tor on Bodmin Moor is called Brown Willy. F’ner f’ner.