Western classic revolvers are all single-action. You thumb back the hammer, then the trigger pull releases it to fire the ammunition. That can provide wonderful, sweet, smooth, light triggers conducive to excellent long-range pistol accuracy.

BUT, in a defensive mode you may wish for double-action where every time you pull the trigger a high-speed bullet is launched at your threatening adversary.

In this video I discuss and demonstrate the differences, applications and advantages of each.