DA/SA help.

[BOOGIE the oily]

Ok, I need your expertise here:

As I've already stated, I have almost no shooting experience.
So I’m trying to understand DA/SA triggers. Not how they work (I already know that), but their pros and cons.
I’ve read a ton of posts about them, and there seems to be as many opinions as there are people using them:
Some people say the long and heavy DA pull is a problem, because it makes aiming on DA more difficult.
Some say that long and heavy pull acts as a safety feature, either when you’re holstering the gun, or when you’re about to let that first shot fly.
Some would like a shorter DA. Some would prefer a longer SA. And the list goes on…

So my questions are (for a SD or a service pistol):

1. Do you think a system in which both DA and SA had the same travel and pull would be an advantage or a problem?

2. If you think the above scenario would be a good thing, would you rather have a short and light DA, a long and heavy SA, or something in the middle?

3. What would be the minimum, in terms of trigger travel, reset and pull, for a trigger to be considered “safe”?

4. How important of a feature is the “double strike capability” on a DA system?

As always, any and all responses are appreciated. But be aware: some of them may prompt new questions.

[marine6680]

There are many opinions on this, and no real hard fast rule.

The question is if the pros and cons of a system fit what you want.

On the whole, the transition between DA and SA is a training issue. Yes it's more difficult to get good with, when it comes to being smooth and fast, but not impossible by any means. Some don't want to bother with it though.

DA is accurate, if you know what you are doing... Practice well, and you can shoot a DA trigger well, even with speed. On the whole, you will not be as fast as a SA or striker, simply due to the longer pull length.

To answer your questions more directly...

1) This is basically impossible... SA by definition only requires minimal movement to actually do the job. To have a long SA pull with a more consistent pull weight, means spring weight is needed through the whole pull, and that affects the DA pull.

Now several DA/SA triggers will come back to rest at or near the farthest point forward, similar to when it is in DA mode... But, the first bit of pull is very light "take-up", that is basically only the weight of the trigger return spring. When the trigger engages the sear, near the rearward end of travel, then you feel the added weight from the resistance of the mechanism. There is no real way to make the whole pull in SA a constant weight, not one that is simple anyway.

Many pistols do not let the trigger come back all the way forward in SA, but they still tend to have some take-up.

It's also not really much of an advantage, nor would it be a disadvantage much either, there is still a pull weight difference... That's the whole point... Training dictates advantage and disadvantage more then the trigger does.

2) The whole point of DA/SA is the longer and relatively heavy DA first pull, acting as a bit of a safety... Or more accurately, as a buffer. Followed by a shorter and lighter SA pull, for faster and possibly more accurate follow-up shots. Mess with that, and you eliminate the point, and don't really gain, and potentially lose.

3) For a safe pull weight, I think the DA pull should be around 8lb at a minimum. Light enough to not be a hindrance, but still enough weight to matter. SA I feel needs to be no lower than 4lb, as too low in my opinion, and you increase the risk of errant shots under stress.

For a DAO trigger, 6lb would be a good weight.

For a SAO, 5-6lb for me as a minimum, as even with a safety, used correctly, it will not be engaged when you are in active use of the pistol. Its there's for administrative tasks like holstering... Same with a striker pistol, no less than 5lb... pull is longer than SA, but there is no manual safety at all.

As far as reset distances are concerned... It's hard to pin down a number there... As good trigger technique will not have much care one way or another. So long as you follow through properly, and don't relax your finger under recoil, you are less likely to fire an errant shot.

4) Second strike is really down to a couple factors... If you train for malfunctions, with immediate action clearing drills, and you have them ingrained into you as an automatic response to a "click" Then the second strike is less of a benefit.

That being said, most people have a tendency to pull the trigger again after a click... Especially those who do not train as much as the higher level shooters.

It could be argued that pulling the trigger a second time is faster than performing immediate action, and that if you verified the chamber was loaded prior to setting off that day, then it's also likely that a second hit will make for a bang.

But it really comes down to when the click happens... First shot or third... Or after a hasty reload?

Plus unknown factors, like... Did the gun function properly, and the chamber has a live viable round, that is capable of going bang on a second hit... Or did the gun malfunction in a manner that the chamber is empty?

So it could be argued that a second hit is no guarantee, and that ensuring a fresh round is in the chamber is a better strategy.

So where you fall in this debate, depends on your views on reliability of the pistol, the likelihood of getting a bad round, and your views on the probabilities of your own errors.


And much of what I said, especially as far as pull weight and such, is my opinion. All you can do is take on what facts can be known as truths, and the hypotheticals, plus the ideas and thoughts of others with informed opinions and knowledge... Then combine that with your own thoughts and make your own choices.

[kozak6]

1. Do you think a system in which both DA and SA had the same travel and pull would be an advantage or a problem?

Big problem. What's the point? It sounds complicated, and there is no advantage over a DAO (double action only) trigger.

2. If you think the above scenario would be a good thing, would you rather have a short and light DA, a long and heavy SA, or something in the middle?

A short and light DA trigger would generally be a good thing, regardless. Due to available leverage, though, it's usually one or the other. Sometimes it can even be either on the same trigger. Look up a DAK trigger.

A long heavy SA trigger is generally known as a bad trigger.

3. What would be the minimum, in terms of trigger travel, reset and pull, for a trigger to be considered “safe”?

That's a matter of opinion. You could probably get by with a lighter trigger on a pistol with an active safety. Consider the debate considering "Glock leg", and whether it's a hardware or training problem. 4-6 pounds is probably about right. A shorter reset is better because it reduces the risk of short stroking the trigger.

4. How important of a feature is the “double strike capability” on a DA system?

Not important at all. Pulling the trigger again is not taught as a part of malfunction drills.

Sometimes, it might be nice if you run across a batch of surplus ammo with hard primers. But it's not necessary.

[arquebus357]

I believe that you need to differentiate between striker fire and hammer fire in discussions about SA vs. DA triggers.

Striker fire is SA ONLY. It really doesn't matter if pulling the trigger compresses the striker spring or not. As long as there is a round in the chamber, all you need to do is pull the trigger. Sort of like a hammerless revolver with a full cylinder.

Hammer fire is well explained above.

I have always been a bit leery of striker fire but I went ahead and got a Ruger American when the compact version was offered. Unlike most others, I find NO safety in a long heavy trigger pull so I opted for the version with a thumb safety. Sorry

[Nathan]

So my questions are (for a SD or a service pistol):

1. Do you think a system in which both DA and SA had the same travel and pull would be an advantage or a problem?

2. If you think the above scenario would be a good thing, would you rather have a short and light DA, a long and heavy SA, or something in the middle?

3. What would be the minimum, in terms of trigger travel, reset and pull, for a trigger to be considered “safe”?

4. How important of a feature is the “double strike capability” on a DA system?

First of all, "some say" a lot of things. I would say most people say things to justify what they have done. What logic or data are they sharing?

1) CZ's custom guns are close to this because reducing spring weight takes weight directly off the DA pull and minimal impact on the SA pull. That combined with the sear hammer engagement that is positive...hammer cocks slightly when pulling trigger makes a more common pull feel. I like CZ, but not for this reason.

2) I would rather have SAO at a weight and pull I can be fast, accurate and safe with.

3) Hard to measure, but I like a 1911 with a fairly long takeup, crisp pull and minimal overtravel. The key is you have to be able to firmly grasp the trigger before releasing the sear.

4) Not at all. You will never use it. I train that when it doesn't go bang, I work the slide. How will I ever learn to try what didn't work the first time again when being shot at?

Ultimately, I find da/SA an unusable system. It was designed as a bridge between DA revolvers and pistols. It's useful life is over. Now it seems to fill a role for people concerned about carrying a loaded gun. They are getting pressure from the Glock people that safeties suck and from non-shooters that say an SAO trigger is a hair trigger.

I have a CZ75. I've trained with it. I can da and SA a double into the target. I also have 1911's that I can double quicker and with much better accuracy. I also prefer the manual safety. If I'm going to press an SA trigger to fire negligently, I probably will do the same with a da.

[BILLG]

There is absolutely nothing wrong with the DA/SA pistols just the way they are.If you can't shoot one well you need more practice.

[Nathan]

Yea Bill, you are probably right.....considering you know nothing about my shooting other than I don't like da/sa. Still, we all appreciate your opinion.

[jmr40]

* With practice a DA/SA can be effective.

* It takes a lot more practice to be effective with DA/SA.

* You are less likely to have an AD on the 1st shot with DA/SA, but after the 1st shot is fired you are more likely to have an AD.

* Simple is better

* DA/SA designs are fading in popularity quickly. I haven't seen anyone in LE carry one in years. Many DA/SA guns once popular are no longer in production and I don't see them making a comeback.

In my opinion a 10-12 lb trigger pull for the 1st shot followed by a 4-6 lb trigger pull for subsequent shots is a bad idea. Having a SAO design with 3-4 lb trigger pulls for every shot may be a good idea for a target gun, but is a bad idea for a SD gun.

Glocks and most other striker fired guns are DOA with ~ 6lb trigger pulls and a short take up for every shot. I feel that is a good compromise between being safe enough but still light enough for decent accuracy.

As long as these designs are carried in a good holster I don't have a problem with them not having a safety. But on the other hand I don't see where having a safety on them detracts one bit. The owner would have the option of using it or not. Most of the DA/SA guns have safety's even though they aren't needed at all. About 50% of DA/SA gun owners use the safety, about 50% only used it as a decocker.

If you're uncomfortable with a striker fired gun with no safety there are several good options that have one. I've owned DA/SA in the past and still own a Sig 226. And while they can work, they are simply more complicated than necessary. I think the design was a compromise to make revolver guys more accepting of semi's back years ago.

[SauerGrapes]

Yeah, I'm sure Sig Sauer is getting ready to discontinue 3\4 of their line of pistols.
And the military will get rid of all the M9's.

I see no reason for revolvers either at this point.
According to the experts here, only thing we need are SA pistols with safeties. Isn't it amazing, someone says this is the only thing that is worth using, and we are all to just capitulate and agree.

[Walt Sherrill]

Originally Posted by arquebus357

Striker fire is SA ONLY. It really doesn't matter if pulling the trigger compresses the striker spring or not. As long as there is a round in the chamber, all you need to do is pull the trigger. Sort of like a hammerless revolver with a full cylinder.

Unless you've got a bad primer...

In making the following comments, I'm using the standard definitions for the various trigger (or is that "action")types.

• A few striker-fired guns are true SA guns. The Springfield XD series striker-fired models were called SA models when first introduced, but now seem to be grouped with Glocks and SIGs, etc. My first Luger (a surplus Soviet-capture) was a true single-action striker-fired gun. As with other true SA guns, if you have a dud round you have to manually recock the hammer or rack the slide.
  
  
• The CZ-100 was a DAO striker-fired gun. The trigger did it all. (I've had several, and they were NOT great triggers, although some owners tweaked them and said they had good results.) Walther also offered a DAO version of their striker-fired P99, called the P990.
  
  
• There are only a few true DA/SA striker-fired handguns -- but many hammer-fired models using that type of action. Walther made the striker-fired P99, a gun that could function in true SA fashion -- because slide movement fully-tensions the striker spring, with the trigger just releasing it, or as a DA gun, with the trigger fully-tensioning and releasing the striker spring (and stiker) in motion. The striker can also be "de-cocked" or left partially tensioned like MOST striker-fired guns. S&W offered the same design as the S&W Model SW99.
  
  
• Most striker-fired handguns (like those made by Glocks, S&W, H&K, SIG, Ruger and FN) are not quite SA, not quite DA, and not quite DA/SA. The Fjestad Blue Book calls the Glock version of this action a Constant Double Action; others call similar systems Modified Double Action. You could as easily call them "Constant Single Action" or "Modified Single Action". Like a true SA (or DAO) gun, and unlike most DA/SA guns, the first and subsequent trigger pulls are all the same. What makes this action type different from other action types is that the trigger can't do anything until after the slide has moved (as when chambering a round) and partially pre-tensioned the striker spring. Why does it matter? If you have a dud round at the range or in a self-defense situation, [U]there is no second-strike capability until the slide is moved.

[adamBomb]

I’ve read a ton of posts about them, and there seems to be as many opinions as there are people using them:
Some people say...
Some say that...
Some would...

I think your answer is right there. There is no right answer. Its all preference. What you are reading are just opinions and they are all subjective. There are scenarios where DA/SA is better than SA and vice versa. My advice, handle as many guns as you can, try them out, etc. see what you prefer, and then train with it. I have learned that I love DA/SA or DAO with that first pull feeling like a true DAO revolver. But there are others that do not like that at all. Neither of us are right or wrong and I can come up with scenarios all day that make one better than the other.

[ShootistPRS]

Boogie,
I come by my preference because I have used revolvers all my life (with a couple exceptions).
I bought my CZ75B for use in 3 gun competition and not for CCW or home defense. I like the exposed hammer and I like the DA/SA trigger because I can have the hammer down on a loaded chamber and the gun works just like my revolver. All I have to do is pull the trigger and it fires, After that it is all single action pull but there isn't enough difference in length of pull or trigger weight that it makes a difference in keeping the sights on target. When I am ready to stop shooting I can let the hammer down on the loaded chamber and the gun is ready to go again. The gun is equipped with a safety that operates when the hammer is cocked so if you trust and use a safety it is there. The safety will not engage with the hammer down on a loaded chamber.

[pblanc]

OK. I'll offer my two cents worth.

I own one double action revolver and at least two pistols each of the following trigger mechanisms:

single action only (hammer-fired)
double action only (hammer-fired)
double action/single action (also known as traditional double action) hammer-fired
striker-fired

I do not own but have shot the Walther P99 DA/SA striker-fired pistol. So I think I can say that I am reasonably familiar with the pros and cons of most of the common trigger actions, at least when it comes to pistols.

I refuse to apply the term DAO or SAO to stiker-fired weapons because I feel the terms have lost all meaning when applied to striker action weapons. I have shot a whole bunch of striker-fired pistols and the length of take-up, trigger pull weight, and the length and force of reset vary dramatically whether the pistols call themselves DAO or SAO.

I think having double strike capacity is never a bad thing, but it is certainly not some kind of deal breaker.

I think that hammer-fired weapons do offer some additional degree of safety when holstering in that the uncocked hammer can be ridden with the thumb to ensure that a foreign body entering or in the holster cannot activate the trigger without being noticed. Among striker-fired pistols, a similar degree of safety can be achieved with most Glock models using the aftermarket striker control device, or "Glock Gadget" which replaces the stock slide back plate.

I do feel that a pistol with a relatively long and at least moderately heavy trigger pull does offer a degree of safety against an accidental or premature discharge if one is using the pistol for self-defense and keeping a round chambered. This can be achieved with either a hammer-fired DAO or DA/SA pistol. Among the striker-fired pistols I have shot, Kahrs come closest (but still somewhat shorter and a bit lighter) to the feel of a DA or DAO hammer-fired trigger action.

I do agree that a DA/SA trigger action requires a bit more commitment to training if the intent is to use the pistol for SD. I know people who own DA/SA pistols who only shoot them at the range, and have never fired them in DA mode. But in a self-defense scenario, you are going to have to fire that first shot DA and any subsequent shots SA, so you must master the longer, heavier DA trigger pull as well as the DA to SA transition. My DA/SA pistols include several different models of Berettas, a Walther, and a SIG P229 and I have not found it very difficult to master the two different pulls, but I know some individuals who have never been able to do so.

For DA/SA hammer-fired pistols, I prefer those with a decocker mechanism only, although I have several Berettas with a combination decocker/safety. One of those Beretta F models I used to carry. When I did so, I carried it with a round chambered, hammer decocked, and safety off. With many DA/SA hammer-fired pistols and nearly all SA pistols, you need to master the engagement and disengagement of an external safety. With nearly all DA/SA pistols, you are going to need to master the use of a decocker.

Some DAO and DA/SA pistols can be challenging for those with smaller hands to shoot well as they have insufficient finger length to get enough finger on the trigger for the leverage required to pull the DA trigger.

The DA trigger pull of a DA/SA pistol, DAO pistol, or double action revolver is typically more difficult for most to master than the trigger pull of most striker-fired pistols or single action only pistols. The sights must be kept aligned throughout a significantly longer and usually heavier pull. Also, DAO pistols and revolvers simply can not be shot as quickly by most people since both the trigger pull and the trigger reset are longer. I have found that single action only pistols, or striker-fired pistols are typically easier for the new shooter to shoot accurately with less training.

For carry purposes and home self-defense I have used several different mechanisms but I tend to favor DA/SA hammer-fired pistols.

As to what constitutes a "safe" length and weight of trigger pull, you will find many different opinions. Different people have very different comfort levels when it comes to trigger weight, just as they do as to the desirability of an external manual safety. It is a waste of time (although a popular one) to argue the relative merits of your particular choice as opposed to that of another.

My personal comfort level for trigger pull weights for a self-defense pistol are around 8 lbs DA and 4.5 lbs SA for a DA/SA pistol, and around 6-8 lbs for a DAO hammer-fired pistol or a striker-fired pistol. My SAO pistols have pull weights in the 4-5 lb range.

As has been said, making the DA and SA pulls on a DA/SA pistol the same length and weight are impossible. In order to fire a hammer-fired pistol in DA mode, the trigger must cock the hammer against the resistance of a mainspring typically starting from a completely untensioned state. And that has to be done using only the strength of your finger. In order to provide sufficient leverage to cock the hammer without having an unreasonably heavy pull, that trigger pull needs to be fairly long. If the pull is made shorter, the pull weight gets heavier.

Furthermore, having the pull weights the same would defeat the entire point of having a DA/SA pistol. If you want a consistent trigger pull weight and length, get a single action only pistol, a double action only pistol or revolver, or a striker-fired pistol.

[Walt Sherrill]

Originally Posted by pblanc

I refuse to apply the term DAO or SAO to stiker-fired weapons because I feel the terms have lost all meaning when applied to striker action weapons. I have shot a whole bunch of striker-fired pistols and the length of take-up, trigger pull weight, and the length and force of reset vary dramatically whether the pistols call themselves DAO or SAO.

The length of take-up, trigger pull weight and the length and force of reset can vary dramatically on DAO and SAO hammer-fired pistols, too. Do you refuse to use the terms with them, too? And then there are the DA/SA hammer-fired guns...

The Luger has a relatively short (and typically light) SAO trigger. The CZ-100, on the other hand, was a hog, with a pretty long and not particularly light DAO trigger. The Walther P99 wasn't outrageous in DA mode, fairly nice in SA mode, and at least as user-friendly as many DA/SA hammer-fired guns.

[WVsig]

Ultimately, I find da/SA an unusable system. It was designed as a bridge between DA revolvers and pistols. It's useful life is over. Now it seems to fill a role for people concerned about carrying a loaded gun. They are getting pressure from the Glock people that safeties suck and from non-shooters that say an SAO trigger is a hair trigger.

I have a CZ75. I've trained with it. I can da and SA a double into the target. I also have 1911's that I can double quicker and with much better accuracy. I also prefer the manual safety. If I'm going to press an SA trigger to fire negligently, I probably will do the same with a da.
Today 08:07 AM

So much fail in this statement. Mr. Langdon clearly has bowed to the pressure.

https://www.youtube.com/watch?v=LDVu-Bs7b4M

I recommend watching these videos.

https://www.youtube.com/watch?v=FsoX26OhDCY

https://www.youtube.com/watch?v=GZplH6zreQI

https://www.youtube.com/watch?v=nod5qLlSGUM

[WVsig]

Originally Posted by Nathan

Yea Bill, you are probably right.....considering you know nothing about my shooting other than I don't like da/sa. Still, we all appreciate your opinion.

Your statements lead people to draw conclusions about you which may or may not be true. When you make statements that are nothing but personal subjective opinion as if they were objective facts you open yourself up to criticism and people questioning your skill and intelligence. Just saying....

[TunnelRat]

I learned to shoot semiautos on DA/SA pistols. I carried SIGs and HKs for years and still own examples of each. I just bought a CZ P-07 for kicks despite the fact that I primarily carry and use striker fired pistols for self defense. When well practiced the DA/SA system can be just as accurate as any other system. I can give a list of instructors if people would like that I have personally seen exemplify this. When I was shooting them primarily and dry firing them regularly I could put that first DA shot exactly where I wanted and the follow ups as well.

For me the rub was this. IMO it requires more practice to maintain the same degree of proficiency as say a striker fired pistol that is not DA/SA. While I still have the time to shoot I grew to a point where I no longer saw the DA first pull as essential for safety. That coupled with the lower skill required of the striker fired pistols as well as the shorter travel and shorter reset compared to the DA/SA pistols I was using at the time lead me to striker fired pistols. I'm happy there, but I will honestly say that maintaining that level of trigger control for the DA/SA system meant I was a better overall shooter back then. My fundamentals simply had to be (again in my experience).

I am enjoying this P-07 currently and shoot, though need to shoot more, my S&W Model 19 in an effort to keep that degree of trigger control in my skillset. If someone issued me or told me I had to use a DA/SA pistol primarily again I would not feel disadvantaged.

[pblanc]

Originally Posted by Walt Sherrill

The length of take-up, trigger pull weight and the length and force of reset can vary dramatically on DAO and SAO hammer-fired pistols, too. Do you refuse to use the terms with them, too? And then there are the DA/SA hammer-fired guns...

The Luger has a relatively short (and typically light) SAO trigger. The CZ-100, on the other hand, was a hog, with a pretty long and not particularly light DAO trigger. The Walther P99 wasn't outrageous in DA mode, fairly nice in SA mode, and at least as user-friendly as many DA/SA hammer-fired guns.

First, the Luger is a striker-fired weapon. Yes, it has a relatively short and light trigger, which is rather typical of striker-fired weapons.

Double action and single action have very easily understandable meanings when it comes to hammer-fired pistols and revolvers. Double action triggers cock and release the hammer. Single action triggers do nothing unless the hammer is cocked.

With striker-fired weapons, unless one has some knowledge of the internal mechanisms, it is unclear to what degree the striker is pre-tensioned by slide reciprocation. When the Glock became the first mainstream striker-action weapon to reach the US market, the BATF needed to apply a classification to its trigger mechanism and the choices were single action, double action only, and DA/SA. Glock convinced or persuaded the Bureau to classify the pistol DAO on the basis that the striker was only partially pre-tensioned by slide reciprocation. This was to Glock's advantage since some LE agencies were beginning to mandate DAO trigger systems for safety reasons. When other striker-action pistols came on the scene, some were also given a DAO classification, even though the striker was tensioned to a much greater degree than Glocks and thus had a significantly lighter trigger pull.

While it is true that the DA pull weight can vary considerably among DAO hammer-fired pistols and double action revolvers, if we set aside the "assisted" double action mechanisms such as Heckler and Koch's LEM system, every double action revolver, DAO pistol, or DA/SA pistol has a very significantly longer DA trigger pull than even the longest striker-action trigger pull I have shot. The DA hammer-fired pull is usually heavier than that of striker-fired pistols as well, although not invariably. The Glock with a NY-2 trigger spring can have a heavier pull weight than some hammer-fired double action pistols and revolvers, especially if the latter have been modified with reduced force hammer springs or trigger return springs.

[marine6680]

Just transfer the function of the hammer to the striker... And the definitions of DA and SA work just fine. The trigger manipulates the firing mechanism. That mechanism can be hammer driven or striker driven.

Why is this concept so hard for people to grasp?


DA, the trigger cocks the firing mechanism, before then releasing it...

SA, the trigger simply releases the firing mechanism. The mechanism can be cocked manually by the shooter (IE a SA revolver) or via movement of the slide. (IE 1911)


Some may cry about Glocks, saying they have muddied the waters on terminology... With their partially tensioned mechanism... So strikers can't fit into the definitions...

Well, hate to break it to you, but there are hammer fired pistols that are partial tension as well. Pull the trigger on a dud, and there is no way to pull the trigger for a second strike. Several of the little pocket 380s are like that. Often these pistols tend to still be considered DAO, even if it isn't a strictly accurate description... But sometimes there are special names for that particular trigger mechanism... I think H&K have something like that, called the DAK or something... I may be mistaken here, on how that system works. I think a couple other big companies did something similar, using special names.


Does the Glock (and other similar striker systems) not fit well into the DA or SA definitions?

No they don't... But that isn't a problem... We are allowed to create another class of trigger mechanism. I personally refer to them as a Partial Tension Striker. You can call them a Partial Tension DA if you want. Or even Partial Tension SA... But I think the last two are over complicating it, by shoehorning old terms into the new. We could even lump strikers and hammers into one term, of Partially Tensioned Firing Mechanism...


There are DA/SA strikers, like the Walther P99. It was mentioned that decocking the P99 basically dropped it to half cock... I do not know if that is accurate or not, I am not familiar enough with that pistol. I do know that its not a new concept, as the CZ 75 with the decocker, drops to half cock... While others like the Sigs and Berettas drop to full decock. Either way... The P99 can operate in a true DA manner, and in a SA manner, in use it may try to operate in an inbetween way, but that is not very relevant.


There are SA strikers... The old Lugers... Several modern pistols, with a few examples like the XD, VP9, PPQ, and M&P (yes it is a SA, no matter what S&W used to say...) SA striker pistols are the current trend.


There are DAO strikers like the aforementioned CZ100...



Look at the firing mechanism and see how it works, and that will tell the story... Yes, its easier to see with a hammer fired pistol, but just because it happens internally, does not make the striker pistols incompatible with current terminology. The Ruger Mk pistols are hammer fired, but it is an internal hammer... And they are definitely SA pistols.


If the trigger is used to cock/tension the action from a full, at rest state, that is DA.

If the trigger simply releases the firing mechanism from a fully tensioned or ready to fire state, then it is SA. Yeah... A striker pistol may have a longer trigger pull than the typical hammer fired SA, but that is there mostly to simulate a light DA trigger feel, to provide some margin of error similar to a DA... That movement isn't needed to actually release the striker though, it's just engineered in take-up. Most of the tension felt in the first portion of the pull is simply spring pressure from the trigger return spring, and possibly the striker block safety. Quite a bit of that take-up could be eliminated with no detrimental effect in many modern strikers.

If it can do both/either method, then it is DA/SA

If the mechanism is partially tensioned by motion of the slide or action... Then it is a Partial Tension system.


A note on the M&P, and it being called DAO. From what I have seen on the S&W site, it is no longer called that, but it was for many years. S&W playing loose with terminology may be another reason people feel the terminologies are not applicable to strikers

It is not a DAO... It uses a rotating sear... The striker is fully tensioned. They claim that it isn't, but familiarity with the pistol will show you that any rearward movement of the striker during the trigger pull is very small, to the point of not being necessary. Trigger jobs on the pistols often eliminate this small movement with no ill effect.

I equate the small movement of the striker with positive sear engagement often found in hammer fired pistols. The CZ 75 is a good example of this... In SA mode, the hammer moves/cams back noticeably when you pull the trigger. It is still considered a SA trigger. That movement is there for positive engagement of the sear and hammer notch for safety reasons... Same as on an M&P.

If you are using a rotating sear to drop/release the mechanism, its pretty much a given that the trigger is SA. Be it striker or hammer. (DA/SA triggers use a combination of a rotating sear and other means, to go between DA and SA modes. The sear is in play in SA mode, and often the trigger bar does the work in DA mode)

[Big Shrek]

Boogie, being that Argentina is where you are...
there are already two great pistols on hand...
the Ballester-Molina and the Sistema Colt.

The B-M is basically a Full-size Star PD.
The Sistema is an Argentine 1911.
Hard to go wrong either way.

Unless you are into plastic...there really is no need for anything else.

[pblanc]

Often these pistols tend to still be considered DAO, even if it isn't a strictly accurate description... But sometimes there are special names for that particular trigger mechanism... I think H&K have something like that, called the DAK or something... I may be mistaken here, on how that system works. I think a couple other big companies did something similar, using special names.

I believe you are thinking about the Heckler and Koch L.E.M. (law enforcement modification) trigger mechanism. This is a two-stage hammer-fired trigger mechanism that utilizes a bobbed hammer. This is hard to categorize as either DAO or DA/SA. It has an internal mechanism that is cocked and partially tensions the hammer when the slide cycles. It might be considered an assisted double action only trigger. The initial trigger pull is long, but smoother and lighter than the DA trigger of a DAO or DA/SA pistol, and the reset is short like a DA/SA pistol and not at all like a DAO pistol.

The DAK (Double Action Kellerman) was a SIG Sauer trigger mechanism that SIG now seems to be phasing out. This was more like a DAO trigger system with an intermediate reset point. This allowed the pistol to be fired if the shooter short-stroked the trigger after the first DA trigger pull. But the trigger pull weight was actually heavier from the intermediate reset point than it was if the trigger was allowed to fully reset.

[marine6680]

Thanks for that info. I never really messed with those triggers.

[arquebus357]

I'm not an expert like others here but:

Is there any striker fired pistol available with a de-cocker device ? If there is such a pistol a double action trigger would be very nice to have. Otherwise you would need to rack the slide.

Actually that striker fired pistol with a de-cocker would be the ONLY time that the term "double action trigger" (the full meaning of the term) makes any sense.

Is this so hard to grasp ?

[pblanc]

Yes. The Walther P99 AS and the Canik TP9 DA are both polymer-frame, striker-fired pistols with a DA/SA trigger mode and a decocker. There may be others.

The P99 I have shot and has already been mentioned in this thread. It is a nice pistol although the location of the decocker takes a little getting used to. I have no direct experience with the Canik TP9 DA.

[Walt Sherrill]

Originally Posted by arquebus357

Actually that striker fired pistol with a de-cocker would be the ONLY time that the term "double action trigger" (the full meaning of the term) makes any sense.

The Walther P990 is a double-action-only (DAO) version of the striker-fired Walther P99. The CZ-100 was also DAO. There was no need for a decocker with either of those guns, as the striker was only fully cocked just as it was released, as part of the trigger stroke.

The P99 does let you decock a cocked striker, as does the Taurus 24/7 OSS -- so the P99 and Taurus 24/7 could both be DA if the shooter had previously decocked them...