Difference between DAO and Striker Fire?

[David007]

Watched a video by Hickock45 doing a review of PF9 vs LC9.

He mentioned that he liked Striker Fire better than Double Action Only in compacts.

What's Striker Fire?

 

[harmon rabb]

The firing pin of a gun can be struck by a hammer, or can be part of a striker.

The firing mechanism of a gun with a hammer can be either SAO (e.g. 1911), DAO (e.g. Sig 250), or pre-set DA (e.g. PF9, LC9, LCP). With a pre-set DA hammer, the hammer is partially cocked by racking the slide, and the trigger cocks it the rest of the way, then releases it when pulled.

Striker triggers can likewise be SAO (e.g. XD, M&P), DAO (I don't know of any), or pre-set DA (e.g. Glock).

Any time I hear someone compare "striker-fired" to "DAO" I want to kick them, because that's wrong and stupid.

 

[K-Rod]

My Kahr P45 is DAO. It's my first DAO weapon. I still can't get my head around what DAO means. I understand the "Double Action" part but when you throw in the "Only", you lose me. I guess I'm not able to keep up with the class???

 

[REAPER4206969]

"Striker fired" is speaking to the firing mechanism.

"DAO" is speaking to the trigger mechanism, or "lockwork." They are completely different aspects of firearm design and can coexist in the same platform.

 

[SDC]

"I still can't get my head around what DAO means. I understand the "Double Action" part but when you throw in the "Only", you lose me."

The original type of double-action automatic pistol lockwork would switch to single-action after the first shot was fired (that is, you'd fire the first shot simply by pulling the trigger all the way through, the slide would cycle AND LEAVE THE HAMMER OR STRIKER COCKED. In a DAO, the hammer or striker drops back to the uncocked position, so you get the same (heavier, but more consistent and theoretically safer) trigger pull each time you fire. So, for something like a S&W 59, you'd get the first shot after a 12-pound trigger pull, and the shots after that would be with a 4- or 5-pound single-action trigger pull. HTH.

 

[Sam1911]

The firing pin of a gun can be struck by either a hammer or a striker

I think it would be a bit more accurate to say the firing pin may be sruck and driven forward by a hammer, or the firing pin may be a striker (or part of a striker) which is driven forward by spring pressure.

 

[harmon rabb]

Good point. I hadn't had my morning coffee yet. Carry on, carry on.

 

[Sam1911]

Actually, you've got me wondering. I can't recall if there are any designs that use an internal spring loaded inertia striker "block" to impact a separate firing pin the way an external or internal hammer would. Seems like someone would have thought of that.

But I guess that's differentiating a hammer from a striker by it's rotation around an axis pin, which might be erroneous.

 

[randytrapper]

I just read somewhere that striker fired pistols are referred to as DAO due to having to be classified for military testing as well as which class to run them in competition. In that same article, IIRC, there is still a lot of gray area with the striker guns falling into different classes due to what the striker actually dose at different stages of the trigger. The example they used was a XD and a Glock being classified differently.
Don't quote me on it, I'm going off of memory. I think the article was by Massad, but the jist of it was it's referred to as DAO, not because of function. But due to familiarity.

 

[Sam1911]

The example they used was a XD and a Glock being classified differently.

Yup. You're right there, in IDPA at least. The xD is classed with single-action autos and the Glock and M&P are classed with DA/SAs, DAOs.

Very frustrating to those of us who use an xDM in those games as the guns are functionally indistinguishable to a large degree.

 

[2WheelsGood]

I still can't get my head around what DAO means.

The conversation is muddy, and some companies intentionally make it even muddier. While this is a bit long, Massad clears it up nicely: Can Semantics Get You Killed - Massad Ayoob

 

[harmon rabb]

Yup. You're right there, in IDPA at least. The xD is classed with single-action autos and the Glock and M&P are classed with DA/SAs, DAOs.

Very frustrating to those of us who use an xDM in those games as the guns are functionally indistinguishable to a large degree.

So with your xdm you're up against guys with high-cap 1911's? Man. Screw that. I'd switch to a Glock

 

[Sam1911]

Yes, but the xDM is arguably faster and, considering the mag limits of the game (and 19+1 capacity of the xDM anyway) I don't complain much about that.

But, seeing as in a match with 100 shooters, 80 will be in SSP (Glocks & M&Ps) and 10 will be shooting CDP (.45s), and one or two wheelguns, I'll only get to compete against a handfull of other ESP guns.

 

[9mmepiphany]

My Kahr P45 is DAO. It's my first DAO weapon. I still can't get my head around what DAO means. I understand the "Double Action" part but when you throw in the "Only", you lose me. I guess I'm not able to keep up with the class???

Part of the confusion is that the term is used differently for marketing purposes.

A true DA trigger will cock the hammer as the trigger is pressed to the rear and then release it to fire the round. As the slide cycles, the hammer will be left cocked...to be release by a SA trigger pull. This action is commonly called DA/SA.

A DAO trigger does the same thing as a DA trigger will, but even after the slide has cycled, the hammer will remain down to be drawn back by the next trigger pull.

Either of these actions will allow the trigger to be pulled again and draw back the hammer should the slide not cycle

A common striker action has the striker held back in the cocked position and then be released as the trigger is pulled.

The Glock and S&W M&P are normally neither cocked nor at rest (uncocked) they are partially cocked when the slide is cycled and the first part of the trigger cocks them the rest of the way before releasing them. These are marketed as DAO, because the manufacturers point out that the trigger action completes, no matter how slight, the cocking of the striker. However these triggers will not cock the striker if it is completely down...the slide needs to be cycled to set the striker for it to function

 

[K-Rod]

Thank you all! That clears it up. My confusion is coming from the "Marketing". The paperwork that came with my Kahr P45 states that this pistol is a DAO. As I started using it, I'm thinking to myself "Whats so special about this DAO? It functions like any of my other Hammerless pistols?" meaning after pulling the trigger, I do in fact have to cycle the slide again in order to fire the next round.

Someone correct me if I'm wrong with what I'm understanding here. When the slide on my Kahr is cycled, the striker is half cocked making this the first "Action". The second "Action" is when I pull the trigger to fire the round causing the striker to continue to full cock then release to discharge. Is it because of these two "Actions" that Kahr can/does market the P45 as a DAO even though you must in fact cycle the slide in order to fire again?

Also, I'm assuming these two "Actions" is the reason for the Lllllloooooonnnnnnnggggg trigger pull & no safety what so ever? Don't get me wrong. Though long, it's very smooth & breaks very nice but I've never had a firearm that didn't have a safety. Is having DA or DAO a good alternative to not having a safety?

 

[Sam1911]

If you have to cycle the slide to reset the striker, then no, it isn't really a DAO.

The double "action" name refers entirely to the two actions performed by the trigger:
1) Drawing the hammer back
2) Dropping the hammer

Remember, the terminology started with revolvers. Single action triggers only dropped the hammer. You had to cock the hammer yourself. When "double action" triggers were invented, they were revolutionary as they could also retract the hammer before dropping it.

Kahr is most likely simply using the term in a loose way to let folks know that the pull is long and it is consistent for every shot (unlike a DA/SA). I doubt they've really sat down to write out an official alternate definition for DAO. (But maybe.) They can say anything they want. It's marketing!

Having a long, relatively heavy pull has been considered a decent substitute for any kind of manual safety for a very long time. DA revolvers have used that as a selling point for over 100 years.

 

[9mmepiphany]

As Sam has stated, you don't have a DAO in the traditional sense, as the striker can not be drawn back from rest by the trigger,...however, it is technically a DAO (and how it is marketed), as the trigger does move the striker backwards as it is pressed to the rear.

The confusion a rises because the terms DA and SA come from the world of revolvers where the differences are more clearly separated. Glock was the first to market their striker action as DAO to qualify for Military and LE contracts...and IDPA competition.

Your Kahr is a bit more DAO than a Glock as it has the distinctive longer trigger travel which allows the additional tactile feedback that is part of the safety margin offered by a DAO trigger

 

[Deanimator]

DAO means that you cannot manually cock the hammer OR striker. The ONLY way to fire the firearm is to pull the trigger, retracting then releasing the hammer or striker.

All a striker is is a way of conveying the tip of the firing pin into the primer without the use of a separate hammer. Instead of having a firing pin on the hammer, or a separate firing pin struck by the hammer, the actual firing pin is retracted and released to strike the primer. A striker fired pistol could be single action, double action OR DAO.

 

[9mmepiphany]

A striker fired pistol could be single action, double action OR DAO

Just curious, How would you classify the trigger system of the H&K P7?

The only true DAO striker fired pistol, with the ability to draw the striker to full cock from rest/release, that comes to mind is the H&K VP70...can you name another?

 

[REAPER4206969]

The only true DAO striker fired pistol, with the ability to draw the striker to full cock from rest/release, that comes to mind is the H&K VP70...can you name another?

Walther P99?

 

[9mmepiphany]

Good catch.

I was thinking of the Heritage Stealth, but now that I think of it that was SAO...it has been so long

 

[2WheelsGood]

Walther P99?

True of the P99DAO and the P99AS, but not the P99QA. Though rare, the P99DAO is a true revolver-like trigger. The AS is DA/SA, but the DAO striker returns to rest after every shot. I think starting this year the P99 is only available in the AS.

 

[Hypnogator]

IIRC, the Glocks were initially marketed as "Safe-Action" pistols.

How "safe" is a matter of opinion. With some of the lighter triggers available, you're carrying the equivalent of a .45 Gov't model cocked and unlocked, with the grip safety tied down! The trigger-pull is merely a little longer than the .45's let-off.

I've always considered "double-action only" to be a contradiction in terms, as I always believed that a double action revolver could be fired after cocking the hammer, or without cocking by pulling the trigger longer and stronger. Hence, the "double action." Others have pointed out, though, that an equally valid interpretation would be that pulling the trigger on a DAO weapon performs the "double action" of cocking and firing the piece.

 

[Manco]

The Glock and S&W M&P are normally neither cocked nor at rest (uncocked) they are partially cocked when the slide is cycled and the first part of the trigger cocks them the rest of the way before releasing them. These are marketed as DAO, because the manufacturers point out that the trigger action completes, no matter how slight, the cocking of the striker.

"No matter how slight" is a key point here, as it's a mere technicality in the case of the M&P, which is something like 99.9% cocked, and then it only nudges the striker back a tiny amount before releasing it. This action is not inherent to its design philosophy (which is really SAO), and if it was done deliberately then the reason must have been so that it could be falsely marketed and classified as DAO (even though it really truly isn't that, either, as you pointed out).

The Glock, on the other hand, is designed to be partially cocked at the ready and then to be cocked the rest of the way by the trigger, no question--still not a true DAO, but at least the trigger does partially cock the striker in a meaningful sense.