movie where guy licks his front sight to see at night

A pragmatic U.S. Marine observes the dehumanizing effects the U.S.-Vietnam War has on his fellow recruits from their brutal boot camp training to the bloody street fighting in Hue.

Vivian, daughter of famed director Stanley Kubrick, shot 18 hours of behind-the-scenes footage for a documentary on the making of Full Metal Jacket. She never completed the project.