I served as a Corpsman at Parris Island in the late 60's, a little over 10 years after "The D. I." was shot. I was in some of the barracks where they filmed some of the indoor scenes. I knew a lot of Drill Instructors and a lot of recruits. I think the movie is as close as any movie to showing the life of a recruit and that of a Drill Instructor. Without a doubt, I think it is the best thing Jack Webb ever did. If you have been in the military, you need to see this movie. This was the way it was. It shows how important it is to take a bunch of raw recruits and turn them into men ready to defend our country. One feature I found fascinating is that most of the characters are played by real Marines, not actors.