Arizona Bushwhackers / Waco

These are two movies from the early days of technicolor with almost identical plots. In each, Howard Keel plays a gunfighter with a problematic past who comes to clean up a Western town with a corrupt saloon owner. In one movie, the sheriff is an ex-convict named Waco; in the the other, he is a confederate spy. Both movies end with classic shootouts in which the gunfighter / sheriff figure saves the town by enlisting the townsmen to shoot a group of Indians or gangsters, finding redemption in the process. Each features a saloon girl and a girl from the town as love interests. I think they even use the same sets for both movies, although they have two different directors.