Never one to repeat himself, after the widely successful Inglourious Basterds, Quentin Tarantino hit the movie world with what he called a Southern, not a Western. It has a lot of Western flavor, but takes place in the American south well before the Civil War. The time period means the firearms are almost all cap-and-ball revolvers, a few lever-action rifles, and shotguns. Since guns from the era before metallic cartridges aren't as various or visually interesting as more traditional "Old West" guns, a lot of the firearms in this movie are a bit anachronistic, having been developed well after the movie's time period.
Django Unchained is a sort of reimagining of a spaghetti western featuring a hero of the same name played by Franco Nero, who has a small cameo in this modernized remake. In the original Django (1966), he drags a coffin that contains a fictional machine gun and along with a "half-breed prostitute become embroiled in a bitter feud between a Klan of Southern racists and a band of Mexican Revolutionaries." The name was used in numerous spaghetti westerns after the original's success, though they have nothing to do with the first Django film.
In Tarantino's remake, the story takes place primarily in the southern U.S. in 1858 and stars Jamie Foxx as Django Freeman, a slave who is liberated by a bounty hunter named Dr. King Shultz (Christoph Waltz) in order to track down and eliminate a gang of wanted men. Shultz and Django strike a deal. If Django helps him bring the brothers to justice, Shultz will help him on his quest to rescue his wife who is still in bondage.
Dr. King Schultz