Heller with a gun
(Book)

"It was a hard land that bred hard men to hard ways. King Mabry survived by his guns. He wasn't proud of his deadly skill, nor was he ashamed. He just lived with it every hard day on the frontier. When a traveling theatrical troupe hired a ruthless killer to guide them through the Wyoming wilderness, King Mabry -- his guns at the ready -- set out to follow their trail, and not blizzards, not Indians, nor the wily guide would stop him" -- back cover.