Action Types... Semi-Auto Handguns

[Ryan in the House]

I'm new to the gun world, and still am unclear on the concept of how action works in a gun. In fact, after trying to read an explaination of it online, I still found myself with more questions in my head than before. So, I figured I'd bring the topic here.

I know there are mainly three types (if not ONLY three types) of actions when it comes to semi-automatic handguns. There's SINGLE ACTION, there's DOUBLE ACTION, and there's DOUBLE ACTION ONLY (DAO?). I also heard of DA/SA (Double Action/Single Action?) and I am foggy on the details of that, as well.

When I was reading that online explaination, it said that DAO pistols operate without manually cocking the hammer back. So, how is the round fed into the chamber? When you use the slide? Then the hammer strikes the pin everytime you use the trigger? So I dont see the difference between that and Single Action, which requires you use the slide (no idea what the term for that is) which chambers the round, and also cocks the hammer into position. So, dont both operate the same?

Alright, I've confused myself even more. Could someone explain to me the differences in the action types?

 

[Ala Dan]

To Muddy The Waters Even Further

Now SIGARMS has introduced pistols in a DAK format. I think
they kind'a have a two stage trigger?

Best Wishes,
Ala Dan, N.R.A. Life Member

 

[mnrivrat]

All action types you mention require that you manualy operate the action slide to strip the first cartridge from the magazine into the chamber. (exception for the tip-up Berreta's)

SA (single action) : This type action in a semi-auto hangun requires that you manualy cock the hammer to fire the first round. When the first round is fired the slide will re-cock the hammer for following single action shots.

DAO (double action only) : This type action cocks the hammer or stricker with each pull of the trigger . Internal linkage between the trigger and stricker/hammer operates independently of the slide operation. The gun does not re-cock during the firing/slide cycle, it only re-cocks with the pull of the trigger.

DA/SA ( double action/single action) : This type auto has a linkage between the trigger and hammer/stricker that will cock and drop the hammer on the first round fired and then allow the slide to cock the hammer for following shots acting now as a single action would.

3:00 am here so I hope I got that pretty much right !

 

[Archangel]

SIG's new DAK action is, from what I understand, a DAO with a 6.5 lb trigger pull (as opposed to ~12 lbs on their standard DAO)

 

[cratz2]

Yeah, there are really even more variations than that...

Single action - hammer is back between each shot, including the first shot. Gun must be carried with the hammer back and the safety on or 'cocked and locked'. 1911s, BHPs are prime examples.

Traditional double action or DA/SA - gun is usually carried with the hammer down on a loaded chamber. First trigger pull is usually two to three times as heavy as subsequent pulls as the first shot requires the trigger cocking the hammer... After that, the slide is cocking the hammer. Depending on design, this actions can be carried cocked and locked for a very minimal difference in shooting speed though they usually have very long trigger resets. Most SIGs most Berettas and most CZs are prime examples.

Full DAO - also called 'second strike capable' by many users of this forum. This is where the hammer is down on the firing pin after each shot. Each trigger pull is typically quite heavy though with training and practice, good shot placement is possible at longer distances. Most full DAOs I've seen are actually variations on a Beretta, Smith or H&K design.

Precocked or pretentioned double action - there is always tension on some part... each trigger pull is consistant as far as trigger reset and weight of pull. But if the round fails to ignite, a second trigger pull will do absolutely nothing. Glock, Kahr, XD are examples.

The most important thing to me is I like a consistant trigger pull. I like the DAK type design, though I don't like H&Ks. I really like the second strike capability though most designs are reliable enough that with good ammo, it isn't required. I've long been a 1911 guy but currently carry a DA/SA CZ PCR. I would love to have it converted to a DAK type action... double action only with second strike capability with about a 6 lb pull. Maybe a bit lighter with some trigger group polishing.

A lot of folks dislike the general DA/SA action because from the first shot to the second shot, the pull is different. I don't like the idea, but that is what I currently carry because I really like the PCR platform other than that.

 

[BHPshooter]

Okay, all semi-automatic handguns have to have the action worked before they are loaded. Working the action (racking the slide) will feed the round into the chamber.

Single Action pistols (ex: 1911, Browning Hi Power) must have the hammer cocked in order to fire. Every time you fire, when the slide recoils, it recocks the hammer and feeds a new round. The trigger feels the same every time you squeeze it.

Double Action (aka, DA/SA) pistols (ex: Beretta 92FS, H&K USP, Makarov, and hundreds more) can fire with the hammer cocked or uncocked. When the hammer is at rest (uncocked), the trigger pull will be a long, hard pull. Every shot after that will act as a single action, because the slide action will cock the hammer when it recoils. For the subsequent single action shots, the trigger pull is shorter and lighter.

Double Action Only pistols (ex: FN Forty-Nine, and variants of many DA/SA pistols) have a long, hard trigger pull for every shot, and generally don't have a manual safety because of that fact. Every time the slide recoils, the hammer follows it back to its resting position, where the long trigger stroke starts again. If a round misfires, the trigger can be pulled again.

Some gun makers will try to confuse people with their own "proprietary actions." This is just marketing hype. Take the Glock's "safe action" for example. The Glock trigger is the same every time, and does not have second-strike capability; therefore IMO it is a Single Action. The same can be said for Para-Ordnance's LDA (Lightning Double Action) -- it is a single action without that "scary" hammer being back. It also does not have second-strike capability, so in my mind, it is lumped in Single Action territory.

----

At first, I thought you were going to ask about actual mechanism action types. You know, like recoil-operated/locked-breech, blowback-operated, gas-retarded blowback, etc.

Silly me.
Wes

 

[possenti]

Suggestion:

Go to a local rental range, and try out the 3 basic types of actions. You'll have a much better understanding with hands-on experience.

 

[WEPS]

 

[benEzra]

More terminology to know (and be confused by ):

All single-action guns and most DA/SA guns have a safety lever that when in the "safe" position prevents the gun from firing. Most higher-quality guns can be carried with the safety either on or off, whichever you prefer. On some guns, the safety locks the hammer back when on "safe" (hence the term "cocked and locked"). On other guns (like DA/SA Smith & Wessons and many Rugers) the safety drops the hammer to the uncocked position ("decocks" the gun) when activated; my S&W 3913 works this way.

On some DA/SA guns, this lever does not have a "safe" position and is used only to safely drop the hammer; in this case, it is referred to solely as a "decocker."

 

[Jim K]

Hi, guys,

Cratz2 wrote about SA pistols: "Gun must be carried with the hammer back and the safety on or 'cocked and locked'."

"Must be"? If one is carrying the pistol on the person and wants it to be available for use as quickly as possible, that is true. But the pistol can be "carried" several ways, including completely unloaded with the hammer down.

Jim

 

[Ryan in the House]

(Keep in mind, I havn't gotten a chance to fire a handgun at the range, yet... with that in mind, prepare to laugh.)

My bro has a Colt/Remington 1911... and it's a single action, I believe. When you pull the slide back, not only is the next round in the magazine loaded into the chamber, but the hammer is also cocked back.

So... you don't have to manually take your finger and pull back the hammer... but instead, you can cock the hammer back AND load the next bullet into the chamber in one motion?

For a DA/SA, when you pull back the slide to load the next round into the chamber, does the hammer cock back too? Or is that first shot done by either a) pulling the hammer back, or b) pulling the trigger to operate the hammer?

 

[monsternav]

...pull back the slide to load the next round into the chamber...

You only have to pull back the slide for the first round, after that the weapons cycle of operation takes care of it for you.

For both SA and DA/SA: Racking the slide loading the first round will cock the hammer.

For SA: The only way to get the hammer down is to pull the trigger. Not advisable (pulling the trigger, unless you want to shoot something). Which is why these weapons are carried cocked and locked. You can, of course remove the magazine, manually work the action to eject the chambered round then, pointing the weapon in a safe direction, pull the trigger to put the hammer down (for storing it or some such).

For DA/SA: The "safety" has two functions, putting the weapon on safe, and decocking (puts the hammer down against the firing pin). Not as dangerous as it sounds, as modern weapons are designed to fire only when the trigger is pulled. Meaning you can hit the firing pin in the back and nothing should happen, usually because of some internal safety device that can only be operated by the trigger. Of course if the weapon has been abused or tampered with...

 

[N3rday]

Okay, lemme break it down for you:

Let's say you have a single action firearm like a 1911, unloaded, with the hammer down. You insert a magazine, and pull the slide back. When you see the gun it will make sense, as the slide hits the hammer on it's trip backwards. Now that a round is in the chamber, you aim at your target and pull the trigger. The ecoil of the shot pushes the slide backwards, which recocks the hammer and ejects the round from the gun.

Double action is basically the same with one exception: The trigger is interconnected with the hammer so that when the hammer is down you can pull the trigger to cock AND release the hammer, i.e. you pull the trigger and the hammer moves upward until it reaches the point where it is cocked, and then falls.
This is Double Action. Since the trigger is doing two things (Cocking AND releasing the hammer) the trigger pull is heavier i.e. it takes more force to pull the trigger far enough backwards to fire. Since the slide moves backwards with each subsequent shot, the hammer is cocked and it behaves just like a single action. Of course, you could always just cock the hammer manually with your thumb and not worry about the double action thing.

 

[Ryan in the House]

So a DA/SA also acts like a Single Action, in that you can pull the slide back to cock the hammer like you would in a Single Action handgun like a Colt 1911?

My natural instinct is probably to do that... if the only difference is that in a DA/SA you can also pull the trigger to fire a shot, then it sounds good to me.

 

[MrMurphy]

With a DA/SA, you carry it hammer down on a live round, and pull the trigger to fire it DA the first time. If you need a more precise shot for some reason, you can just thumb back the hammer (without touching the slide since the round is already in the chamber) and put it in single action mode.


The Glock type action, where you just pull the trigger, or the single action trigger, where you just off-safe and fire, are similar in basic operation (squeeze and it goes bang) however their internal operation is different.

 

[N3rday]

Just FYI:

The advantage to double action guns is that when a round fails to fire for whatever reason, you can just pull the trigger again to detonate the round. With a single action, you would have to recock the hammer with your thumb or, on a non double-action gun where there is no external hammer (Glock, for example), pull the slide back to recock the striker.

Many double-actions come with what are called 'decockers'. On such guns there isn't a 'safety', per se, but the safety, when thumbed down, will lower the hammer from single-action mode to double action.

Have you learned the four rules of firearms safety yet? I would get on that .

 

[Brasso]

Let's look at it as if we were firing each type:

1. Single Action. We'll use a 1911 or BHP as an example.
You insert magazine.
Rack the slide which cocks the hammer and inserts a round.
You fire the gun. The empty case is ejected and the hammer is
cocked for the next round.

2. DA/SA. We'll use a Sig as an example.
You insert a magazine.
Rack the slide which cocks the hammer and inserts a round.
Now you have two choices.
1. Fire the gun in single action mode which fires, ejects the case,
and cocks the hammer, and inserts another round in the
chamber.
2. Decock the gun back to double action which requires a long
trigger pull because you are actually cocking the hammer as
the trigger is pulled. The round is fired which ejects the
empty case and cocks the hammer back into single action
mode and inserts another round into the chamber.

3. DAO. We'll use a Beretta DAO as an example, although most guns come in both DA/SA and DAO.
This mode works the same as #2 except that the hammer always
stays in double action and is cocked as the trigger is pulled. It
never resets to single action.

 

[cratz2]

"Must be"? If one is carrying the pistol on the person and wants it to be available for use as quickly as possible, that is true. But the pistol can be "carried" several ways, including completely unloaded with the hammer down.

True enough... guess I should have said, 'Typically folks that decide on carrying a single action pistol do so because of trigger or platform preference... If one is afraid to carry a single action pistol cocked and locked, one might strongly consider a DA/SA, a DAO or one of the Kahr/XD/Glock type actions'

That better, Jim?

 

[Mad Man]