[ROCKLOBSTER]

A revolver...is the kind of old-style technology that would cause someone to cock the trigger then pull each time and so a new round would load and fire

Not exactly.

I guess my S&W 38 "single action" revolver is a semi-automatic then.

[Gaffer]

Single action on a revolver means that when you want to shoot, you first have to pull back on the hammer to move the cylinder into alignment. You then pull the trigger, and it does not bring the next round in the cylinder into alignment. If you can rotate the cylinder by only pulling the trigger, it is not single action.