Wade Preson played Christopher Colt, a traveling gun salesman who was really an undercover government agent. Donald May played Chris Colt's cousin Sam Colt.
This late 1950's western was created and produced by Roy Huggins ("Cheyenne", "Maverick"). Andrew Duggan guest starred in the pilot as a character named Jim Rexford. Huggins used almost the same name for the lead character of his "Rockford Files" series a decade and a half later.
Like all Warner Brothers shows, "Colt 45" had a great theme song: "a legend bolt but he knew that colt-Colt 45".
Gallows at Granite Gap / Young Gun / The Gypsies / Blood Money
Tar and Feathers / Calamity / Trial by Rope / Showdown at Goldtown
Small Man / A Time to Die / One Good Turn / Judgment Day