I have spoken with two men who successfully defended themselves during a bear attack (not a charge, an in-contact attack). Both used DA revolvers in their strong hand while fending the bear off with the other hand/arm. Both fired multiple shots into the bear's head/neck area. Such a defense would be near-impossible with a SA revolver.

"I'm gonna have to science the schit out of this." Mark Watney, Sol 59, Mars