“Gun Boss of Tumbleweed” by L. Ron Hubbard
Publication date: April 1949
Original publication: Thrilling Western
Story description: Blackmailed into acting as a hired gun by a ruthless rancher, Mart Kincaid decides to get from under his thumb by putting his trigger finger to work in a fiery showdown.
Currently available as part of the Stories from the Golden Age series, in the book Gun Boss of Tumbleweed.