Firearm Basics - Single Action, Double Action, and Striker Fired















So you’re new to guns and you have some questions?  Well, I’m glad you came here.  I’m sure you’ve heard the terms Single Action, Double Action, and Striker Fired thrown around before, but do you know what they mean?

These terms are describing the action of handguns.  Action meaning how the trigger interacts with the hammer (or striker), and how the hammer interacts with the firing pin.  Perhaps you may be unfamiliar with the parts that I have just named.  Don’t worry, I’ll show you some pictures now, but in a future post and video, I’ll go over all of the basic handgun parts.

DOUBLE ACTION
So let’s start with double action.  Double action (also shown as DA) is very common in modern day handguns.  They are especially common with revolvers.  On a double action handgun, when you pull the trigger, the hammer moves back with the trigger, and when they reach their breaking point, the tension on the hammer and trigger is released, the hammer slams forward, and it hits the firing pin.

This is also common on some semi-automatic handguns like the Sig P226, but like most double action revolvers, these firearms also have the ability to fire in single action as well.  We will get into that in a second.  For now, let’s cover Double Action Only.

You may see the phrase Double Action Only (shown also as DAO) thrown around a lot typically with something that does not have an exposed hammer.  Examples include the SCCY CPX-2 or the Smith and Wesson Model 340PD.  What this means is simply the handgun can ONLY fire in double action.  When you pull the trigger, the hammer moves with it.  It does not have the ability to be fired in single action as well like many modern day revolvers and semi-autos can.  So what is Single Action?

SINGLE ACTION
Single action (SA) is not the most common action anymore.  It was most common in old school revolvers, and now in modern day adaptations of old school revolvers.  One of the most famous firearms today that still uses single action exclusively is the 1911.  Single action means the hammer must be in the “cocked position” (must be back) for it to fire.  If the hammer is forward, pulling the trigger like on a double action will do nothing.

You ALWAYS see this in the movies where the main character will be dramatic and pull the hammer of some gun back with his/her thumb.  That is taking a double action, and turning it into single action.  So do you always have to pull the hammer back?  Maybe yes for an old revolver, but on a semi-automatic handgun, the slide of the firearm will move back and forward with each shot.  When the slide moves back, it pulls the hammer back with it, allowing you to fire again.



STRIKER FIRED
So now we’ve come to Striker Fired.  This is what is featured on most of the polymer wonder pistols out there today.  So far double action and single action have something in common: they both use hammers to strike a firing pin.  Striker Fired handguns do not use a hammer.  Instead, they use what’s called a “striker”.

Basically what a striker is, is a different version of a firing pin.  It has a latch on the bottom that gets pulled back when slide is pulled back, and when the trigger is pulled, that latch is disengaged, flies forward, and strikes the bullet.  Like a Single Action handgun, the “hammer”, which in this case is a “striker” has to be pulled back to fire.  Since you cannot pull a striker back manually, you have to pull the slide back to engage the striker.

When the handgun fires, the slide will move back then forward re-engaging the striker.  Now the process can be repeated.


CONCLUSION
There you have it.  You have mastered the knowledge of what Single Action (SA), Double Action (DA or DAO), and Striker Fired is.  See the video below for more details and visuals about all this.  Was something not clear?  Do you have another question?  The Random Firearm is here to help!  Ask in the comment section below, or head over to our Facebook page and ask them there.  You can also find us on Twitter and YouTube!




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