The Heat shootout scene was used to train US Marine recruits.

Michael Mann’s Heat (1995) is one of the greatest films of all time and one of my top ten favorites.
It was the first time Robert De Niro and Al Pacino shared the screen, but the film has so much more to offer than its iconic cast.
Mann strived to imbue the film with a strong sense of realism. This authenticity is evident in both large and small things. He spent seven months shadowing the Los Angeles Police Department’s Robbery-Homicide Unit.
It’s this deep dedication that makes Heat’s iconic shootout scene one of the greatest in cinematic history.
All the actors underwent three months of firearms training with former SAS soldier Andy McNab, and the actors playing the robbers were tasked with planning a real bank robbery, including “scouting the scene” without getting caught.
Because Mann was adamant about shooting on location, the sequence lasted several weeks as they could only work on weekends.
Instead of dubbing the gunfire later, Mann placed microphones at strategic locations throughout the filming set. For Mann, action is essential. In the film, the sound of gunfire echoing off the skyscrapers adds to the visceral thrill of the scene.
The bank robbery and shootout sequence was shown to U.S. Marine recruits at MCRD San Diego as an example of the proper way to retreat under enemy fire.
And the part where Val Kilmer performs a quick reload under enemy fire was shown as an example of how to perform this maneuver correctly.
Heat has inspired films – The Dark Knight, The Town, Criminal Squad – and video games – Grand Theft Auto 3 and 5 and Payday 1 and 2.
Heat is the seminal, modern film about robbery and heist. It was made in 1995. Yet, no film has been made since then with such a profound sense of authenticity. It feels so real that the robbers copied Heat.
And when I interviewed people in prison, they would refer to Heat. And when I interviewed the FBI, they would refer to Heat.
So, aside from the fact that I was disappointed to always be in Heat’s shadow, I can tell you with certainty, with great authority, that Heat is the only movie that is cited as a real movie by people who actually make this kind of thing. – Ben Affleck (director, The Town)
My God, I love Heat .