P.S. The popularity of Cowboy Action shooting competition in the U.S. has made it possible for movie producers to easily find reproductions of correct period firearms. (Clothing as well.)
Charlie Waite, (Kevin Costner) fired a Colt model 1873 pistol and a Winchester model 1873 rifle.
Boss Spearman (Robert Duval) carried a Remington model 1875 pistol, a Winchester 1873 rifle, and a mule-ear shotgun of undetermined make.
Percy (Michael Jeeter) Used a Winchester model 1866 "Yellow Boy" rifle.
Contrast this with the John Wayne movie, THE COMMANCHERO'S, which takes place in 1848. Wayne's pistol was first produced in 1873, his rifle in 1892, and he was "trading" Winchester model 1894 rifles made to look like 1860 Henry's.
I hope westerns are making a come-back . . . especially if they are as accurate as Open Range.