When the clear-cut ethics of western movies turned out to be an idealized myth, the genre took a violent turn with rougher, bloodier visions of life in the Old West. The western genre started out with an optimistic view of justice and a morally black-and-white perspective of good versus evil. However, as time went on and the world became a lot more complicated, filmmakers challenged these tropes and conventions with morally gray antiheroes, real hardship on the frontier, and lots and lots of blood. Directors like Sam Peckinpah and Sergio Corbucci upended the genre’s traditions to deliver darker, grittier, and bloodier western movies.

https://screenrant.com/western-movies-violent-bloody/