SS Pistols fire one round only as a simple action and resets recoil before their next shot.
SA Pistols fire one round as a simple action, or three rounds as a complex action. Recoil builds until reset with a non-attack acction.
SA/BF Pistols act the same as SA pistols in SA mode. In BF mode they fire three rounds as a simple action, or six rounds as a complex action. Recoils builds until reset with a non-attack action.
Helps sometimes in this game to have things spelled out plainely,