I responded to a similar question regarding pistol usage in the American West during the mid-to-late 19th century not long ago, here: https://www.reddit.com/r/AskHistorians/comments/6lfm6x/how_common_were_pistols_in_the_american_west/

Here is a response I made to a question about how close Hollywood's imagining of the "Old West" jives with what historians believe: https://www.reddit.com/r/AskHistorians/comments/55uvfk/how_accurate_is_hollywoods_portrayal_of_what_we/

TD:LR - Duels of the classic "draw!" at high noon variety were rare, and except for Wild Bill vs. Dave Tutt and the Earps et al at the O.K. Corral, there aren't a lot of examples of them. They did happen from time to time, sure, but most gunplay of this era was somewhat cowardly (shooting in the back, ambush, etc.). You would have been a lot more likely to die from falling off your horse or wagon, or get sick from drinking bad water, than getting killed in a gunfight.