The Gun That Won the West was, of course, the Springfield Rifle, the "central character" in this inexpensive Columbia western. The plot concerns the efforts of the War Department to build up a chain of defense posts to protect railroad workers from Indian attacks. Dennis Morgan stars as real-life frontier scout Jim Bridger, who guides the Army through Sioux Territory. Though Bridger is a friend of Sioux chief Red Cloud (Robert Bice), there's no telling what might happen should the railroad men be left at the mercy of Red Cloud's duplicitous second-in-command, an Indian brave known as Afraid-of-Horses (Michael Morgan). With the aid of the newly developed Springfield, Bridger and his cohort Jack Gaines (Richard Denning) are able to keep the peace. In the tradition of previous Sam Katzman productions, a goodly portion of The Gun That Won the West is comprised of stock footage from previous westerns.
~ Hal Erickson, All Movie Guide