What is the name of this movie?

I know it's a western, but I can only remember parts of the story. It's about a group of guys who fought for the south during the civil war. they return home after the war. In their town the sheriff and his deputies are corrupt and murder one of the aforementioned guys' younger brother/sister (can't remember) and burn down his families ranch. then the group decides to take revenge. something like that. I do remember though that the last scene in the movie shows the group having a shoot-out with the sherriff in front of the building that he was in in the middle of the town, they kill the sherriff and i believe the movie ends there. Another thing that I remember is that the movie is pretty violent, I think that it would be rated R.