I've had half burned powder kernals, usually 2400, get under the extractor of a DA revolver and tie it up.
The only issue I've had with a SA revolver was with a Ruger super blackhawk. If that little spring-loaded plunger inside under the hammer gets rust in the hole so it can't move, like from factory bluing that wasn't cleaned out well enough, the hammer won't come clear back. It's ... disconcerting. Its one of the things I disassemble now and clean thoroughly when I get a new Ruger single action.
Tom
