What is a single action pistol?

A single action pistol is a type of firearm that relies on a hammer to fire each round. The trigger on this type of pistol only performs one action - releasing the hammer to strike the firing pin. The shooter must manually cock the hammer before firing the first shot, after which the action can be repeated by simply pulling the trigger. Single action pistols are desirable for their relatively light trigger pull, which aids in accuracy. The most famous example of a single action pistol is the Colt 1911, which was designed for the US military and has since become iconic in the world of firearms.