 SPOILER: The production company had to keep a diver on the set  during the filming of the climactic scene filmed on a pier in which  Callahan shoots the bad guy. When the gun would jam, which it did  frequently, Eastwood would in a fit of rage throw the gun a  considerable distance into the water. The diver would retrieve the  gun, which would be dried out, repaired, and reloaded for the next  take.