Ever since Justus D. Barnes fired his pistol directly at the camera at the end of 1903’s “The Great Train Robbery”, filmmakers have been smitten with the poetry of gun violence. When gangster films and westerns became two of the most popular movie genres in the 1930s, the shootout became an essential bit of cinematic business; audiences wanted to see the good guys and bad guys blast away at each other before the credits rolled. In 1995, Michael Mann unleashed the shootout to end all shootouts in his crime epic “Heat.” It was so realistic that when a couple of heavily armored bank robbers turned North Hollywood into a war zone in 1997, reporters immediately referenced Mann’s movie. As we acknowledge Mann’s classic, let’s look back at some of the big screen’s most memorable shootouts.