Colt .45 (1957)

"There was the right, there was the wrong; the gun was quick, the man was strong; and peace was made when they'd arrive. A lightning bolt when he drew that Colt forty-five..." The exploits of Christopher Colt, United States government undercover agent who poses as a salesman for the Colt .45 repeater, as he strives to ensure law and order on the frontier in the 1880s.