It seems as though the cattleman revolver is supposed to be the “good guy” weapon while the double action is supposed the “bad guy” weapon because of their special grips. Also because the cattleman is the default weapon for Arthur and most of the “good” gang members (John, Sadie, Hosea, Lenny, Sean, and Kieran) while the double action revolver is used by two bad characters of the gang, Micah, who’s the villain of the game and Javier, who later becomes an antagonist in the first game.