Netflix is borderline useless when it comes to movies but the 3-Episode miniseries Hatfields and McCoys from late last year just popped up on Netflix. Not necessarily Old West, but a similar time-frame...two American families who got into quite a blood feud following the Civil War.
I know the story but haven't seen the mini-series. Will start it here shortly. Just a heads up for anyone looking for some sixgun inspiration. This would be a cool game/scenario/campaign to run using Old West rules etc.