The Durango Kid rides again in Lightning Guns. As ever, the masked Durango (alias Steve Brandon) is played by Charles Starrett, who this time around is on the trail of a gang of cold-blooded killers. Rancher Dan Saunders (Edgar Dearing) is held responsible for the killings because of his opposition to a politically expedient dam project. Durango believes that Saunders is innocent, and he intends to prove it.

When Steve Downey arrives to reopen his brother-in-law's gold mine, he finds a war between the ranchers and the miners. Ashton has had the water poisoned killing cattle. When Ashton's men find Steve's hat, they kill Tom Tavish and frame Steve for the murder. Escaping jail the Durango Kid goes into action.

A young married couple whose plans for their life together haven't turned out as expected decide to rob the bank where the husband works of $100,000, then hide the money in a safe place and return for it after they serve out their sentences. All goes according to plan until they get out of prison, when they find that they're being trailed by an insurance investigator and the husband's old cellmate, who has decided that he wants a cut of the money.

Stage line owner Brent has his men robbing Halliday stages and when his manager Waring learns of it, Brent has him killed. Jeff Waring arrives and takes his uncle's job. He soon learns what's happening and the Durango Kid goes into action. This keeps Halliday going and gives them a chance to get the mail contract by winning the stagecoach race.