Much grimmer than the movie, but more accurate to the source material?

Well, maybe. From 2006, the Lone Ranger #3, written by Brett Matthews, art by Sergio Cariello.

John Reid may not have been able to save his parents and brother, but he does have some impressive woodworking skills, as he carves a mold then melts his Texas Rangers badge to make a silver bullet. Before he starts his quest for vengeance, the newly masked Lone Ranger visits the grave of his mother, and in turn is visited by Tonto, who looks more like Conan here. The Ranger pistolwhips Tonto, then apparently sets fire to his house and takes off on Tonto's horse, unwilling to be deterred from his mission.

It has to be disappointing, or at least anti-climactic, when he finds his target dead, an apparent suicide. Tonto somehow got there really quickly, and does return the punch owed to him, but John seems spent, giving Tonto his silver bullet, saying he only had the one murder in him. Still, there was money there, which Tonto suggests could be put towards a horse. Elsewhere, Butch Cavendish makes something like a campaign speech, then receives a telegram from his hired killer, advising that the Lone Ranger remained. On the next page, the killer murders a woman, then has to go back when he hears a baby crying, to finish the job...that's a little dark for this. But there's a little light in the end, when at the horse lot...I'm pretty sure that's not where you buy horses, but whatever...John is introduced to the toughest horse out there, a silver-colored beauty recovering after a fight with a buffalo. Do horses fight buffalo that often? Maybe Silver's just a jerk.