It's only called "Bang" because,while watching my little brother play Black-ops ,i was working on this track. He was playing through the campaign and had the TV loud. He was on the level where main characters of the story were being forced to play Russian Roulette. I don't remember it clearly 100% but i remember hearing "YOU SHOOT,G.I.! BANG BANG" and that's where the name came from.
The melody is a different story.