The Fourth Gunman — Merle Constiner

The forces he opposed were ruthless and clever-so much so that they fooled the very ranch owner they were robbing. Without even the help of the victim, Netfield had to find a way to unmask the marauders and catch them red-handed in their cattle swindle. If he failed he knew there'd be wholesale slaughter in Kirkville, and that he'd be the first to get a six-gun send-off!

Merle Constiner (1901-1979) was an American pulp author who wrote both detective fiction and Westerns. The Fourth Gunman follows the conflicts between lawless rustlers and a cool-eyed saloonkeeper for control of a western town.