Bonanza S01E19 - The Gunmen

On a cattle buying trip to Texas, Hoss and Little Joe are mistaken for a pair of hired killers recruited by a feuding family in their bid to wipe out a rival clan. Their efforts to convince the town otherwise are hindered by the fact that the Cartwrights are dead ringer for the gunfighters in question - Big Jack and Shorty Jim Slade. Written by David Bassler