Trigger Actions Explained: Single Action, Double Action, and Beyond

The trigger is the heart of your firearm’s operating system. It’s the primary interface between you and the gun, but the mechanics behind it are often misunderstood. Terms like Single Action, Double Action, and Striker Fired get thrown around, leaving many shooters confused about what they actually mean and why it matters.

Understanding your firearm's action is not just for gunsmiths—it's essential knowledge for any serious owner. It affects your trigger pull, your first-shot accuracy, the weapon's safety features, and its overall feel. This guide will cut through the technical jargon and give you a no-nonsense breakdown of how these systems work so you can choose, operate, and shoot your firearm with confidence.

What are Single Action and Double Action?

 

At its core, the trigger initiates two potential tasks:

1. Cocking the hammer or striker.

2. Releasing the hammer or striker to fire the round.

The difference between action types comes down to how many of these tasks the trigger performs when you pull it. Single Action means the trigger does one thing. Double Action means it does two. It’s that simple.

 

Single Action (SA)

 

Single Action is the classic mechanism, the original semi-automatic design. As the name implies, the trigger has only one job to do.

 

How Does Single Action Work?

 

In a Single Action firearm, the trigger’s only function is to release a hammer that is already cocked. You must manually cock the hammer first, either with your thumb or by racking the slide. With the hammer back, the trigger pull is typically very short, light, and crisp. Once the shot is fired, the rearward motion of the slide automatically cocks the hammer again for the next shot.

Think of it like a pre-set mousetrap. All the tension is already in the spring; the trigger just lets it go.

 

Pros & Cons of Single Action

 

• Pros: The short, light trigger pull is incredibly conducive to precision. Because the trigger does very little work, it’s easier to press it without disturbing your sight picture, making SA firearms famously accurate. This is why they dominate in many shooting competitions.

• Cons: The need to manually cock the hammer for the first shot adds a step to the firing process. Carrying an SA pistol with the hammer down requires you to cock it under stress, which is slow. The alternative, carrying it "cocked and locked" (hammer back, safety on), is perfectly safe but requires rigorous training to master the safety disengagement during the draw.

Double Action (DA)

 

Double Action triggers were designed for simplicity and added safety, doing two jobs with a single pull.

 

How Does Double Action Work?

 

With a Double Action firearm, a single, long pull of the trigger first cocks the hammer all the way back and then releases it at the end of the pull, firing the gun. There's no need to manually cock the hammer. You just pull the trigger. This is the system used in most modern revolvers and many semi-automatics.

 

Pros & Cons of Double Action

 

• Pros: Its main advantage is simplicity. There are no external safeties to fumble with—the long, heavy trigger pull acts as a built-in safety feature, making accidental discharges less likely. It's a very deliberate and safe system for a first shot in a high-stress situation.

• Cons: That long, heavy pull is the biggest drawback. It requires significant finger strength and control to press the trigger smoothly without pulling your sights off target. For many shooters, this leads to decreased accuracy, especially on the first shot.

 

Double Action / Single Action (DA/SA)

 

The DA/SA system is a hybrid, designed to offer the best of both worlds: the safety of a Double Action first shot with the precision of Single Action follow-up shots.

 

How Does Double Action / Single Action Work?

 

The first shot from a DA/SA pistol is fired in Double Action mode—a long, heavy, and deliberate pull. After that round fires, the cycling slide automatically cocks the hammer. Now, the firearm is in Single Action mode. Every subsequent shot will have a short, crisp SA trigger pull until the gun is empty or you use the decocking lever to safely lower the hammer back to the DA position.

 

Pros & Cons of Double Action / Single Action

 

• Pros: You get a safe, deliberate first shot without needing to manipulate a safety, followed by fast and accurate SA shots. It’s a versatile and effective system used in many legendary service pistols.

• Cons: The primary challenge is mastering two completely different trigger pulls in the same firearm. The transition from a heavy DA pull to a light SA pull can be jarring and often causes shooters to throw the second shot if they haven’t trained extensively for it.

 

Striker Fired

 

The striker-fired system is the modern standard, found in the vast majority of polymer-framed pistols today. It offers a simple, consistent trigger pull without the use of an external hammer.

 

How Does Striker Fired Work?

 

Instead of a hammer, these firearms use a spring-loaded pin called a striker. Racking the slide partially pre-cocks the striker. When you pull the trigger, it finishes cocking the striker and then releases it to fire the round. The result is a consistent trigger pull for every single shot—from the first to the last.

 

Pros & Cons of Striker Fired

 

• Pros: The biggest advantage is consistency. The trigger feels the same every single time, which makes it incredibly easy to learn and master. The lack of an external hammer means there’s nothing to snag on clothing, and the internal design is highly reliable and simple to maintain.

• Cons: Some purists complain that striker-fired triggers can feel "spongy" or less crisp than a high-end SA trigger. Additionally, most striker-fired guns do not have "second-strike capability"—meaning if a round fails to fire, you have to rack the slide to reset the striker, rather than just pulling the trigger again.

 

Which is Best for You?

 

There is no single "best" action. The right choice depends entirely on your intended use and personal preference.

• Single Action: Best for competition shooters and enthusiasts who prioritize pure trigger quality and mechanical accuracy above all else.

• DA/SA: A great choice for those who appreciate traditional hammer-fired guns and want the added safety of a DA first pull without compromising on follow-up shots.

• Striker Fired: The ultimate all-rounder. Its simplicity, reliability, and consistent trigger pull make it an excellent choice for self-defense, duty use, and general range work. This is the system most new shooters should start with.

Conclusion

 

Your firearm’s trigger action is fundamental to its performance. Each system offers a different blend of safety, accuracy, and simplicity. By understanding the core differences between Single Action, Double Action, and striker-fired systems, you can make a more informed decision about what you carry and shoot. The best way to know what’s right for you? Get to a range and try them all. Your trigger finger will tell you which one fits best.