Striker-Fire??

[270rocks]

What is a striker-fire pistol?

[Marshal Halloway]

A pistol design which employs an internal striker mechanism to detonate the primer. In operation, the pistol is normally in a partially cocked condition. Pulling the trigger completes cocking the action, and then releases the striker mechanism to fire the pistol.

[Dharmaeye]

Spring propels the firing pin directly - not a hammer hitting the firing pin.

[MikeO]

Striker fired guns can be single action (XD), DAO (Glock), or DA/SA (Walther P99 AS).

[Edmond]

Walther has 3 different trigger modules

AS, Anti Stress, DA/SA

QA, Quick Action, SA only

DAO, Double Action Only

[Sponsor]

[Big Frank]

Spring propels the firing pin directly - not a hammer hitting the firing pin.

That's it. No hammer.

[Lonestar]

Striker fired guns can be single action (XD), DAO (Glock), or DA/SA (Walther P99 AS).

NOT TRUE..  I had been searching for answers after looking at several autos (GLOCK 22, Springfield XD, Smith MP)  claiming DA/DAO, but noticing striker/firing pin only released after racking slide, inadvertently cocking the striker/hammer, unlike a true DA/DAO, such as revolver. 

I have found one place to accurately describe striker fire action from NRA Certified Pistol Instructor.

Why Glocks are NOT Double Action
http://members.cox.net/guntraining/glocks.htm

below are a few definitions and highlights...

Glock claims their guns are "Double Action Only". They are in fact striker-fire, SINGLE action, no matter what Glock and the box says. This misunderstanding has annoying operational implications, and possibly dangerous defensive implications.

Definitions:
Single Action: Pulling the trigger does ONE thing : if the hammer has been cocked, it will release the hammer. Trigger pull is light, short, and consistant between first and subsequent shots. Example: Star Firestar Plus.

Double Action: Pulling the trigger does TWO things : it will first cock the hammer if it hasn't been cocked, and then it will release the hammer. DA Trigger pull is longer and heavier than SA, but the user can cock the hammer first if they want to fire in "Single Action Mode." If the gun is semi-automatic, the first shot is DA, subsequent shots are SA due to the slide cocking the hammer for you, resulting in differing trigger feel as described above. Example : Beretta 8045, Hoekler and Koch USP series, etc.

Double Action ONLY: Any DA gun which does not allow pre-cocking the hammer because the hammer won't stay cocked, and is often bobbed or hidden. No decock is ever needed, and trigger pull is consistent between first and subsequent shots. Example: AMT Backup

Striker Fire: Rather than a hammer, an internal striker is cocked and released to fire. The striker is cocked by the first motion of the slide, and there is no way to decock other than squeezing the trigger.

Any "true" double action gun will cock the hammer by squeezing the trigger, which means you don't HAVE to cock the hammer manually before the first shot as with a single action. In contrast, a Single Action gun you have to cock the hammer before you squeeze the trigger.


Glock claims to be "double action only" because :

1) You can't cock the hammer from a "hammer spur" externally, normally a sign that the gun is DAO.
2) In normal practice, pulling the trigger makes it go off, suggesting (falsely) that the trigger is cocking the hammer like a DA.
3) Trigger pull feels consistant between shots, suggesting DAO.

All three are wrong because :

1) Glock can be (and is) cocked externally for the first shot, but its done by the slide motion involved with loading the first round into the chamber rather than an overt hammer. This is true of any other semi-auto gun -- unless it really IS a DAO gun, any semi-auto can be cocked by racking the slide if you wanted).

2) The gun IS in fact cocked for the first shot before the trigger is pulled, and stays that way once cocked until fired, just like any other SINGLE ACTION. The second shot is cocked by the first, etc.

3) Just as with any other NON-DAO semi-auto, Glock counts on the process of chambering a round to cock the gun for you between shots. Since you always fire in single action mode, the trigger always feels the same.


How can I prove my Glock is Single Action?

There are a lot of Glock afficianodos who will SWEAR that their Glock is DA, until I have them dry fire twice in a row to similate a misfire. Remember what I said the definition of a DA gun is? DA cocks the hammer for you from the trigger, and will do so every time.

I said before that Glock's claim to be DAO has gotten people killed.

[Big Frank]

Striker fired double actions are relatively rare but they do exist. The Walther P99 is a DA/SA striker fired pistol. When you fire it in the double-action mode the striker isn't pre-cocked. The trigger actually draws the striker back then releases it. It has second strike capability and if you dry fire it you can just keep pulling the trigger and it keeps cocking and releasing the striker. Some Taurus pistols, FN FortyNine, S&W SW99, and Colt All American 2000 are all striker fired with second strike capability. I'm not sure about Kahr.

The Taurus 24/7 Pro pistol is a whole different design. According to Wikipedia: Pre-set hybrid triggers are similar to a DA/SA trigger in reverse. The first pull of the trigger is pre-set. If the striker or hammer fail to discharge the cartridge, the trigger may be pulled again and will operate as a DAO until a malfunction is cleared or the cartridge discharges. This allows the operator to attempt to fire a cartridge after a misfire malfunction. The Taurus 24/7 Pro pistol (not to be confused with the first-generation 24/7 which was a traditional pre-set) offers this feature as of 2006.

[m25operator]

Dharmaye has it the most right, the firing pin is retracted, against spring pressure and then released to fire the cartridge, be it rifle or pistol, Bolt action rifles use this method almost exclusively. Jumbo Frank and I went round and round on this one, I agree to disagree with his findings, and they can be read on another thread, but to answer the question, Dharmaye had the most correct answer, in firearms, very often there is no CORRECT ANSWER.. The Taurus Mellinium, has second strike capability, you pull the trigger again, and it brings the striker back and releases it again, no change from the first trigger pull,  Kahr does not have this capability, though I wish it did, as I love mine.... but then again, it's never been necessary.

This is why I stick to my interpretation of double action, the firearm has 2 ways of firing,  cocking the hammer and pulling the trigger, or just pulling the trigger. It just makes sense. The term DAO, DA/SA are relatively new terms, and should not be necessary, since the original S&W double action revolvers, should be, DA/SA by this discussion, or DAO's, but they were not, saying they are double action since they can be shot by pulling the trigger, ignores the fact, that they can be cocked by the hammer and fired, what is called single action. I wonder how far, the revolver market would have gone until now, if they all read the new, S&W, Ruger, H&R, Colt, etc.... were identified as double action ONLY!!  Why is there even a term DAO, if there was not a double action first?

[Lonestar]

Why is there even a term DAO,....?

Hammerless revolvers, SW 640.  It is physically impossible to shoot as SA. 

DA revolvers with exposed, SW 637, or shrouded hammer, SW 649 can be shot either DA or SA.