I've been thinking about this since you posted and can't make up my mind. Seems a lot of good movies have inaccuracies, and sometimes the bad ones will surprise ya. ut my choice for accuracy, for now, is "Last Stand at Saber River". Old Tom has a way with movies. I saw the "making of" this flick and it showed Mr Selleck discussing a shootout scene and he made the point of actually COUNTING the shots he had fired and saying he would "have one left". No "seven shooters'" for him! :-D
As to least accurate, John Waynes "Comencheros". I love John Wayne, and this is a great movie, but Winvhester 1892s and Peacemakers before Texas was a state? Ouch! :oops: