What Is a Double-Action Pistol?

When answering the question, “What is a double-action pistol,” all attention should immediately turn to the trigger. In the simplest terms, the trigger’s singular action releases the hammer from a cocked position so it can strike the firing pin or primer to ignite the gunpowder inside the cartridge case. A pistol with a trigger that only releases the hammer is a single-action pistol. Double-action pistols have a trigger that has a double function. It will release the hammer from the cocked position, and if the hammer is not cocked, pressing the trigger will cock and release it. As simple as that might seem, it’s actually a bit more complicated.

What Is a Double-Action Pistol Trigger?

In order to understand what a double-action pistol is, you first need a general understanding of handguns. There are ultimately two types: revolvers and pistols. A revolver is a handgun that has a cylinder with multiple chambers that rotate behind a barrel, whereas a pistol is any handgun with a chamber that’s part of the barrel. A pistol can have a bolt or a break action, or it can be a semi-automatic. Revolvers can be either single- or double-action, but only semi-automatics pistols can be double-action. The double-action identifier is not so much about the handgun as it is about trigger function.

When you insert a magazine inside a double-action pistol and cycle the slide to load a cartridge into the chamber and barrel, the slide cocks the hammer. As the slide goes forward, the hammer remains cocked. Since the hammer is already cocked after you load a double-action pistol, what’s the point of a trigger that will cock the hammer? Well, it’s a safety thing. Because some — particularly in law enforcement — felt carrying a pistol with a cocked hammer and a light single-action trigger pull was unsafe, they wanted to de-cock the hammer until it was time to shoot, which led to the addition of a de-cocking lever. When this lever is pressed, the hammer falls forward but will not fire the pistol. Now, if you want to shoot the pistol you must either manually cock the hammer or pull the double-action trigger that will cock and release the hammer.

In theory, this works perfectly. However, the distance and amount of force needed to press a double-action trigger and cock the hammer is much more than the amount of distance and force necessary to press the trigger to release the hammer from the cocked position. After firing, a pistol’s slide cycles to eject the empty case and load a new cartridge, it also cocks the hammer. This means that your first shot with a double-action pistol that’s de-cocked will require a lot more trigger pressure and movement than subsequent shots. Trigger consistency is a big part of being able to shoot accurately, and a lot of shooters did not like the inconsistency between the first and subsequent shots. So, the double-action-only (DAO) pistol was created.

DAO

When you insert a magazine in a DAO pistol and cycle the slide to load it, as the slide goes forward the hammer falls, but the pistol will not fire because the trigger has not been pressed. This can be a bit disconcerting unless you know the kind of pistol you’re dealing with. Once loaded, pressing the trigger forces the hammer to the rear and then releases it to fire the pistol. But, unlike with a double-action pistol, where the slide cocks the hammer as it cycles, with the DAO pistol the hammer follows the slide forward. The advantage of the DAO pistol is that the trigger press is the same for every shot because the trigger cocks and releases the hammer for every shot. Because it seemed some could not decide between a DA and a DAO pistol, for a short time in the early 90s, Browning offered the BDM pistol which was switchable from DA to DAO. It was a failure. Though DAO pistols were once popular with law enforcement, they’re now mostly extinct because of striker-fired pistols.

Striker-Fired

You could argue that the modern striker fired pistols like the Glock and Smith & Wesson M&P are nothing more than highly refined DAO pistols. The primary difference is that striker fired pistols do not have a hammer. Instead, they have a spring-loaded striker that’s partially cocked by the cycling of the slide and then released by the trigger. Like a DAO pistol, the trigger pulls of a striker fired pistol remains the same for every shot, but the force needed to press the trigger is less, but still a bit more than with a single-action pistol.

Given the popularity and wide acceptance of striker fired pistols, by the military with the Sig P320, by law enforcement with various Glocks, and especially with civilian shooters with similar pistols, it’s unlikely DA or DAO pistols have much a future. However, time will tell. The single-action 1911 pistol has been around for more than a century and it continues to gain popularity. Who knows what the future holds.