A double-action revolver is one where pulling the trigger can both cock the hammer and then release it to fire the shot, instead of you having to manually cock the hammer first. Many double-action revolvers can also be fired in “single-action” mode by cocking the hammer with your thumb first, which gives a lighter, shorter trigger pull for that shot.

Basic meaning

  • In a double-action revolver trigger pull does two jobs: it cocks the hammer and then drops it to fire.
  • In a single-action revolver, you must manually cock the hammer each time; the trigger only releases the already-cocked hammer.

How it works in practice

  • With a typical double-action revolver, you can fire by just pulling the trigger from hammer-down, which is the “double-action” mode.
  • You can usually also thumb-cock the hammer first, then use a light trigger press to fire, which is the “single-action” mode on the same gun.

Pros and cons

  • Double-action trigger pulls are usually longer and heavier, which can make precise shooting a bit harder but is often considered safer for defensive carry.
  • Having both double- and single-action options lets shooters choose: faster close-range shooting in double-action, or more precise shots using single-action.

Related terms you may see

  • DA/SA revolver : Can be fired both double-action and single-action as described above.
  • DAO (double-action-only) revolver : Designed so you cannot cock the hammer for single-action; every shot is fired by the long double-action pull.

Bottom line: for a revolver to be called “double action,” its trigger must be able to cock and release the hammer on its own, without you manually cocking the hammer first.

Information gathered from public forums or data available on the internet and portrayed here.