For all their complicated inner workings, the act of firing a gun is relatively simple. You point it at your target, make sure the safety is off, and pull the trigger. It’s often as simple and complicated as that. The trigger and action mechanism control the majority of the weapon’s functions.
So, what are the different types of trigger actions currently in use, and what are the benefits of each?
1. Single-Action Only (SAO)
One of the most common types of triggers is the single-action model. You’ll often see this trigger design on handguns. As its name suggests, pulling the trigger on a single-action firearm will only do one thing — drop the hammer — so you’ll have to manually cock the hammer if you want to fire the weapon. If you pull the trigger before you cock the hammer, nothing will happen.
SAO triggers are popular because they aren’t complicated and they don’t require a heavy pull to fire the weapon. This often makes it easier for you to hit the target because it doesn’t need as much force to pull, so there’s no risk of pulling yourself off target while you’re trying to fire. Every trigger pull will feel the same. With modern SAO triggers on semi-automatic pistols, you no longer need to cock the action before every pull.
Single-action revolvers will need to be cocked manually before every shot. SAO semi-autos are often carried with a round chambered and the hammer cocked, ready to fire if the need should arise. The action is stopped by a manual thumb safety you’ll need to disengage.
2. Double-Action Only (DAO)
Next, we have the double-action trigger. These are most commonly found on revolvers and get their name because they carry out two actions when you pull the trigger. They both cock and release the hammer.
These have a heavier trigger pull than the SAO style. DAO triggers take these design elements to the next level. There is typically no external hammer for you to cock, with the trigger pull handling both cocking and firing within the gun’s internals. In the cases where there is an external hammer, it’s usually “bobbed” and cannot be cocked manually.
Like single-action handguns, DAO firearms will have the same trigger pull every time you fire the weapon.For DAO firearms, the heavy trigger pull is considered a safety feature, and they will not typically have a manual thumb safety. It’s harder to pull the trigger and discharge the weapon by accident, so if you shoot someone, it was likely intentional.
3. Double-Action/Single-Action (DA/SA)
Double-action/single-action triggers are designed to give you the best of both worlds. Choose how you’d like to fire your first shot — by manually cocking it like a single-action firearm or by pulling the trigger and letting the double-action mechanisms do the work for you.
On DA/SA semi-auto pistols, after the initial heavy DA trigger pull, the action will shift into a lighter SA pull, enabling faster and smoother shooting. This is great for speed, but it can throw off your accuracy until you learn to adapt if you’re not prepared for the shift. When you’re finished shooting, most DA/SA pistols will feature a decocking lever or button to safely lower the hammer.
On DA/SA revolvers, the default trigger pull is a consistent heavier double-action pull, but you have the option to manually cock the hammer to take a lighter single-action shot. This is good if you’re target shooting or firing at distance. These are also often referred to simply as double-action revolvers, but they function more like a DA/SA firearm.
DA/SA firearms are a very popular choice for military and law enforcement, but they can be great for civilian use as well. If you decide to add one of these trigger types to your collection, make sure you take the time to practice and adapt to the two different trigger styles contained within one firearm.
4. Striker-Fired (SF)
Now we’re leaving the hammer behind entirely in favor of a wholly internal system. The striker-fired, or SF, trigger uses a firing pin striker instead of a hammer. Chambering a round begins the process of cocking the action and pulling the trigger finishes it, sending the round out of the barrel and, hopefully, into your target.
You’ll often see this sort of trigger action in rifles and shotguns, but Glock’s semi-automatic handguns, as well as a number of modern polymer-framed pistols, are also known for employing this kind of trigger.
Striker-fired triggers are popular because they function well in a variety of environments. We feel comfortable taking rifles and shotguns hunting with us because the lack of an external hammer reduces the risk of dirt or debris affecting the firing action. Likewise, striker-fired pistols are popular for carry because dirt and lint is less likely to impede function.
The only downside is that the lack of an external hammer or safety lever means you’ll need to take extra steps to secure the firearm to prevent accidental discharge. However, many striker-fired firearms do include an external safety and other internal safety features.
Choosing Between Trigger Actions
Choosing between trigger actions is a matter of personal preference. Some people prefer the ease of a single-action trigger, while others prefer the added safety of a heavy double-action trigger. For everyday carry or self-defense, an SAO or DAO handgun might be your favorite. However, you might be uncomfortable sticking a cocked-and-locked single-action pistol into your holster. Whatever the case, we recommend experimenting with different trigger styles to figure out what works best for you. The results might surprise you!
What is your favorite style of trigger action? Let us know in the comments below!
Editor’s note: This post was originally published in July of 2021. It has been completely revamped and updated for accuracy and clarity.