DAO auto...?

[gunner]

How does a DAO auto work?I thought all autos were single action after the first round.....

[Guest bkelm18]

Striker fired pistols (XDs and Glocks) are considered DAO.

[nightrunner]

actually unless i am misinformed the XD is single action in the way it fires releases the striker

[Shima]

I don't think the XD is a single action, but I'm no professional.

[MizuUsagi]

IDPA says it's a single action, but rest of the world considers XD's DAO.

[Guest Astra900]

DAO example would be a PT145 Taurus. To be Double action only, the action of pulling the trigger must draw the firing pin from a rest position into a cocked position and release it from that position in one movement. The XD IS a single action because the firing pin is cocked when a round is charged into battery. The pulling of the trigger releases the pin from from that position in the same manner the releasing of a cocked hammer would. The fact that it doesn't have a hammer classifies it a striker fired pistol like mentioned before.

To get get your head bent around the principal; Always think of a DA revolver, in how the pulling of the trigger draws the hammer back and releases it in one fluid motion.

But what do I know, no one listens to me:D

[glockster157]

How does a DAO auto work?I thought all autos were single action after the first round.....

Asta900 has it right. A DAO, is a common term for a trigger cocking pistol. The guns you are probably familiar with are SW 59 series, Beretta 92's, Sigs, CZ's, etc. All of these guns have a long first trigger pull that cocks and fires the pistol, after which the slide's rearward action cocks the hammer for all susequent shots in that string. It is actually more complicated than just cutting off the single action sear of these pistols as the hammer does follow the slide back to battery so there are some internal differences. DAO's make really good carry guns as they have the same trigger pull for each shot. So as long as it has a smooth trigger like a beretta, I like them but then, I really like revolvers and prefer to shoot them double action.

[Wingshooter]

The DAO works like Astra and Glockster said.

I carry a DAO. It is the H&K USP compact LEM. It has a long first trigger pull but a short and lighter trigger reset for subsequent shots. The bobbed hammer returns to the DA (forward) position after every shot.

[strickj]

Nope,wrong on the XD.It actually semi-cocks the firring pi as you pull the trigger which would make it a DA.

If you put your finger on the cocked indicator while pulling the trigger you can actually feel this happening.

Edited March 28, 2009 by strickj

[Guest Astra900]

I don't know where ya'll are getting this, but take another look at the definition of single action and double action.

The XD cocks when the slide is slid back, the sear engages and holds the firing pin in a cocked position until the trigger is pulled. Any perceived movement you're feeling of the firing pin is just the mechanism doing it's job. There is nothing in an XD's trigger group that actually pulls the firing pin into a compressed position. Break one down and look. When you pull the trigger, the only thing that happens is a small tab of metal withdraws into the grip frame releasing the firing pin from it's cocked position. If it wasn't a single action the existence of a cocked indicator on the rear of the slide would be of no use. Also, look at the distance of total travel for the trigger. ANY AND ALL DAO pistols have a very long trigger travel. DA/SA like the beretta 92 also have the looooong trigger travel on the first shot because when the trigger is pulled it is cocking the pistol before it fires it. But the 92 is not a DAO because the weapon stays cocked after the first shot. The 1911 is a SA. It must be manually cocked before it can be fired for the first time, either by cocking the hammer on a loaded chamber or racking the slide to load the chamber which cocks the hammer in the process.

Another reason you know the XD is single action and not double action? Duds. Yep, pretend you have a bad primer that didn't go off when you pull the trigger. How do you try again with an XD? You must pull the slide out of battery to cock the mechanism again. Well a Taurus PT is a DAO, you can just keep pulling the trigger over and over to see if it fires. OR if you have a SA/DA like a Walther P38 or a Paraordnance LDA 1911 you could try again without moving the cartridge in the chamber.

Summary, XD=SA

[strickj]

I didn't say it completely cocks,I said semi-cocks.The traditional definition between DA,and SA is like you stated earlier between a revolver,and a 1911(true DA,SA).

XDs do not fit into the definition of a SA.

Although,in your defense I suppose it doesn't really fit into true DA definition ether.

Edited March 28, 2009 by strickj

[deerslayer]

Another reason you know the XD is single action and not double action? Duds. Yep, pretend you have a bad primer that didn't go off when you pull the trigger. How do you try again with an XD? You must pull the slide out of battery to cock the mechanism again. Well a Taurus PT is a DAO, you can just keep pulling the trigger over and over to see if it fires. OR if you have a SA/DA like a Walther P38 or a Paraordnance LDA 1911 you could try again without moving the cartridge in the chamber.

I believe that this argument is not valid. IIRC, some true DAO handguns must be cycled before the action can be operated again. In other words, after the gun is dry-fired, the slide must be racked in order for the trigger to cock and drop the hammer--no double strike capability. S&W 59 series is an example, I think, but I could be wrong.

[gunner]

the reason this topic peaked my interest is my cousin bought a S&W Sigma .40 and it says DAO on it.He asked me if he could carry with one round in the chamber.In order to do that you would have to insert a loaded magazine and cyce the slide......so the gun would NOT be cocked.....right?

[nightrunner]

no a sigma would not. a sigma is just a glock copy, in a pure sense. it is a pure DAO

[gunner]

k....... thanks

[Guest 2HOW]

The Taurus mil pro series are Hybrid trigger pistols. Every pull is single action with a second strike capability if the round does not fire.

Single action (SA)

A single-action trigger, sometimes single-action only, performs the single action of releasing the hammer or striker to discharge the firearm each time the trigger is pulled.[1] Almost all rifles and shotguns use this type of trigger.[1] Single-action semi-automatic pistols require that the hammer be cocked before the first round is fired.[2] Once the first round is fired the automatic movement of the slide cocks the hammer for each subsequent shot. The pistol, once cocked, can be fired by pulling the trigger once for each shot until the magazine is empty. The M1911 is a single-action pistol that functions in this manner.[2]

[edit] Single set trigger

A set trigger allows a shooter to have a greatly reduced trigger pull (the resistance of the trigger) while maintaining a degree of safety in the field. There are two types: Single Set and Double Set. A Single Set Trigger is usually one trigger that may be fired with a conventional amount of trigger pull weight or may be 'set' by usually pushing forward on the trigger. This takes up the creep in the trigger and allows the shooter to enjoy a much lighter trigger pull.

[edit] Double set trigger

As above, a double set trigger accomplishes the same thing, but uses two triggers: one sets the trigger and the other fires the weapon. Set triggers are most likely to be seen on customized weapons and competition rifles where a light trigger pull is beneficial to accuracy.

[edit] Double action (DA)

Invented by Robert Adams, a double-action trigger performs two functions when pulling the trigger, first cocking the hammer then releasing it to discharge the firearm. When this term is applied to revolvers, the trigger also rotates the cylinder. Though this is technically a third action, it is correct to refer to the mechanism as double-action. Most pistols and revolvers with a double-action trigger mechanism retain the single action functionality: See the Double action/Single action (DA/SA) description below.[1]

[edit] Double action only (DAO)

A double action only is similar to a DA revolver trigger mechanism however there is no single action function.[3] For semi-automatic pistols with a traditional hammer, the hammer will return to its decocked position after each shot.[3] For striker-fired pistols such as the Taurus 24/7, the striker will remain in the rest position through the entire reloading cycle. This term applies mostly to semi-automatic handguns; however, the term can also apply to some revolvers such as the Smith & Wesson Centennial and the Enfield No. 2 Mk I revolvers.

[edit] Double action/Single action (DA/SA)

A double action/single action firearm combines the features of both mechanisms. Often called traditional double action, these terms apply almost exclusively to semi-automatic handguns.[3] The function of this trigger mechanism is identical to a DA revolver. However, the firing mechanism automatically cocks the hammer or striker after the gun is fired. This mechanism will cock and release the hammer when the hammer is in the down position but on each subsequent shot, the trigger will function as a single action.[3] The Mateba Autorevolver is a hybrid revolver that functions on a DA/SA system. However, it is different in function than either a conventional revolver or semi-automatic pistol. The H&K USP is a good example of a DA/SA semi-automatic pistol. On many DA/SA pistols (including the USP) there is the option to cock the hammer before the first shot is fired. This removes the heavy pull of the double-action. Also, there is often a de-cocker to return the pistol to double-action.

[edit] Pre-set

Pre-set hammers and strikers apply only to semi-automatic handguns. Upon firing a cartridge or loading the chamber, the hammer or striker will rest in a partially cocked position. The trigger serves the function of completing the cocking cycle and then releasing the striker or hammer. While technically two actions, it differs from a double-action trigger in that the trigger is not capable of fully cocking the striker or hammer. Glock pistols use a pre-set striker mechanism. Examples of pre-set hammers are the Kel-Tec P-32 and Ruger LCP pistols.

[edit] Pre-set hybrid

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.

[S&WForty]

This article on a S&W 990L is more of an article about what defines a DAO. It's good reading.

http://www.handgunsmag.com/featured_handguns/sw99ol_081005/index.html

[Guest PerazziTM1]

DAO is just that "Double Action Only" You can not cock the hammer with your thumb and fire the gun. The Colt Pony (380 auto) is DAO.

Also, revolvers with the bobed off hammers are DAO.

Hope that helps,

[Guest HexHead]

Then there's the Para LDA trigger. DAO. Every trigger pull is exactly the same. The slide partially cocks the inner hammer, pulling the trigger cocks the outer hammer and fires the pistol.

Sweetest feeling DAO trigger out there too.

[Guest RISC777]

the reason this topic peaked my interest is my cousin bought a S&W Sigma .40 and it says DAO on it.He asked me if he could carry with one round in the chamber.In order to do that you would have to insert a loaded magazine and cyce the slide......so the gun would NOT be cocked.....right?

When the slide is cycled on a Sigma it cocks the pistol. If a loaded magazine is inserted, it will also be loaded at that point (14).

The alternative is to insert a round in the chamber, release the slide, then insert a full magazine. At that point you have a cocked weapon with one in the chamber and 14 more in the magazine (14 + 1).

Your cousin can carry it with a round in the chamber, certainly, though your cousin must remember the only true 'safety' on a Sigma is the individual's brain.

[nightrunner]

The alternative is to insert a round in the chamber, release the slide, then insert a full magazine. At that point you have a cocked weapon with one in the chamber and 14 more in the magazine (14 + 1).

i have read that this is not reccommended.(putting a round in the camber manually) can cause premature damage of some sort. it is easier to insert a full mag, chamber a round and then takeout the mag and top it off with one more round

[Guest RISC777]

i have read that this is not reccommended.(putting a round in the camber manually) can cause premature damage of some sort. it is easier to insert a full mag, chamber a round and then takeout the mag and top it off with one more round

Either works. It's not the nicest thing to do to your firearm releasing the slide and letting it "slam" into place. I should have not described it in the fashion that I did. -- If you insert one manually and close the slide more gently than just releasing it, it won't go fully to battery and have the ejector catch as it should, so as you described above would be the better way to go.

I, depending on the situation or mindset, have done it both ways though.

My Sigma has withstood a great deal of (non-intentional) abuse to varying degrees (including dropping the thing into mud). But, it's fed every time, ejected every time, went boom every time, etc.

[DaveTN]

“Action Type” threads are always interesting. You almost have to have the guns in your hands and feel the difference.

For example… A Sigma and a Glock are the same? You can put whatever name you want on the type of actions, but most people want to know the feel or end results. If it weren’t for the Sigma; S&W would have never produced a bad firearm. And it is because of the trigger on the Sigma. You have to pull the trigger on the Sigma all day long to get it to fire.

On the other hand if you bump the trigger on a Glock it will go off. The Glock has (According to Glock ) a “Safe Action”.

(If it were any safer it would shoot everyone in the room without anyone touching it. Like in the Plaxico video )

[Guest RISC777]

Ah, but I thoroughly enjoyed working the action and trigger on my Sigma.

It's nothing like it was out of the box. It's my usual daily carry.

I understand some not liking or appreciating it, but I have found no faults with mine.

[gunner]

When the slide is cycled on a Sigma it cocks the pistol. If a loaded magazine is inserted, it will also be loaded at that point (14).

so its not a true DAO like say the S&W 442 J-frame he bought his wife....