Guns of Diablo was cobbled together from two episodes of the TV series The Travels of Jamie McPheeters. 14-year-old Kurt Russell plays Jamie, an orphaned boy heading westward with a wagon train. Charles Bronson tops the cast as wagon scout Linc Murdock, who runs into difficulties when he meets old flame Maria (Susan Oliver), who is now married to corrupt lawman Rance Macklin (Jan Merlin). The jealous Macklin has Murdock arrested, but Maria frees him, permitting Murdock and Jamie to embark on a new adventure involving a "lost" gold mine. Curiously, Dan O'Herlihy, Kurt Russell's costar on Travels of Jamie McPheeters, does not appear in this ersatz feature.