The Way of the Gun
is a tough movie to watch, because the main characters (played by Ryan Phillippe and Benicio del Toro) are not good guys at all, and neither is anybody else you'll meet in this movie. The plot centers around the kidnapping of a pregnant Juliette Lewis, who is tied to a shady organized crime figure played by James Caan.
This movie could have gone a lot of ways, most of them b-movie bad, but if I remember my trivia right the brother of the director (Christopher McQuarrie) was a Navy SEAL, and pretty much lived with the actors. If I had to pick a movie that was closest to 100% realistic in weapons handling from start to finish, The Way of the Gun would be it. A great example of this is a scene where Benicio del Toro exchanges words with someone in a parking lot, and fires a round off. As soon as he heads back into the motel room, while talking to his partner, you see him topping off his magazine!
The climax of this movie
is a rather lengthy gunfight involving a lot of people at a run-down hotel south of the border. You'll see the proper use of a tactical sling, one-handed reloads, the proper way to clear a room with a .308, and a lot more. But like I said, nobody in this movie has clean hands, and things don't end well for anyone.