Day of the Evil Gun is a 1968 American traditional Western starring Glenn Ford, Arthur Kennedy, and Dean Jagger.

Lorn Warfield (Glenn Ford), who had been away a long time, sets out to rescue his family, with the unwanted help of his neighbor Owen Forbes (Arthur Kennedy).

Forbes, a decent, humane rancher, is also in love with Warfield's wife and feels guilty that he did not try to prevent the kidnapping.

However, Mexican bandit DeLeon (who has dealings with the Indians) believes Warfield's story that he hid his money before he was caught and cuts him loose.

It turns out that Addis, who is actually a corporal, and the rest killed the real captain so that they could trade two wagons full of weapons and ammunition to the Apaches in return for an army payroll the latter recently captured.