Son of God’s Country (1948)

Bill Sanger has his men out raiding and killing to obtain the ranches along the route that he knows the new railroad will use. He then kills the editor that received a letter that would expose him. But the editor earlier hid the letter in a chamber of his gun. Marshal Monte Hale arrives and eventually suspects Sanger and breaks into his house. After a gungight Sanger catches him and with one shot left shoots Monte. But he is using the editor's gun.