The antagonist might be called Jack/Jake, in his 20s, a murderer responsible for killing many familes, has shaggy hair very much like Kurt Cobain.
In the closing scenes the protagonist (probably a sheriff but can't remember) finally shoots Jack/Jake. The wound is clearly going to kill him but he stays alive, hunched forward in the saddle of his horse. I have a vivid memory of this moment in the movie and not much else.
Many people seem to immediately believe the film I am talking about is Shane, because that film features the hero slumped on his horse at the end. Shane is definitely 100% not the film in question :)
Any help would be massively appreciated as I've been searching for this film for over 10 years. I have every intention to follow up any suggestions :)