Noobie DA vs. SA question

[rogerjames]

I own a ruger 357 revolver, and I understand the DA/SA difference when it comes to wheelguns. I am a little confused about DA/SA difference in autoloaders. I've seen some 1911's that appear to be SA only. Does that mean the first round has to be manually racked and the subsequent pulls would be DA?

 

[Steve C]

The first round must be manually racked or chambered in both single and double action semi auto's. In conventional pistols the hammer or striker is cocked upon racking the pistol. The hammer may be lowered either manually or by using the hammer drop safety if the pistol is so equipped. In the 1911 and other SA pistols the hammer will have to be cocked to fire the pistol.

1911's are single action. The trigger only does one thing and that's release the cocked hammer to fire the pistol. Single function = single action. The 1911 is self cocking upon firing but that has nothing to do with its action being single or double.

In a double action semi automatic like the Beretta 92, Sigs, Rugers, etc the trigger performs 2 functions i.e. the DA trigger will both cock the hammer and release it when the hammer is down, the gun will fire only if there's a chambered round. 2 functions hence the "double" in double action.

The conventional DA trigger will also act as a single action on subsequent rounds as the gun self cocks.

Some semi auto's are DA only in that the hammer or striker is not left cocked after the slide is racked or a round in fired. In these pistols the trigger performs the cocking and releasing of the hammer or striker every time the pistol is fired.

Then there's the unconventional actions that are still Double Action but somewhat of a hybred. Glock's are typical of this type action and Glock calls theirs a "safe action". The striker is retained in an intermediate position under too little tension to set off a round if accidently release like a half cock. Upon firing the trigger retracts the striker back a bit more before releasing it to fire the weapon.

Dawoo's and some of the new Brownings have a similar system that Dawoo calls a tri action in that their hammer can be fully cocked but then can be pushed forward to the down position. Upon firing the trigger brings the hammer back with no spring pressure (as the hammer springs is held fully compressed) and then releases the hammer to fire. The Dawoo and I suppose the Brownings both act as conventional DA/SA semi auto's if the "tri-action" feature isn't used.

 

[possum]

sa means that the hammer has to be manually pulled to the rear, before you can fire the weapon. you can do this by pulling the hammer back. or when you insert a magazine, rack the slide and the rd will enter the chamber and the hammer will be to the rear, and you are ready to rock. a sa pistol can only be fired with the hammer in the rear postion.

DA/SA double action can be fired with a long da trigger pull, the first time, and the working of the slide from the recoil will cause the hammer to stay back after firing, and every subsequent shot will be in sa, unless you drop the hammer with the decocker. da/sa can be fired with the hammer in the down or back postion, just different weight trigger pulls.

hope this helps! hopefully my explinations make sense!

 

[Bobo]

A single-action (SA) gun has only single-action capabilities.
A double-action (DA) gun has single-action and double-action capabilities.
A double-action only (DAO) gun has only double-action capabilities.

SA, DA, and DAO may be applied to revolvers or semi-autos.
SA/DA only applies to semi-autos.
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SA (Single-action) = The gun's hammer/striker must first be fully cocked manually or by cycling the slide, the trigger's only job is to release the hammer/striker.

DAO (Double-action Only) = The gun may have one or more of these capabilities only:
The hammer/striker may be fully cocked by the trigger, and released by the trigger.
Or the hammer/striker may be half-cocked by cycling the slide, then fully cocked and released by the trigger.

DA (Double-action) = The gun must have one or more of these double-action capabilities:
The hammer/striker may be fully cocked by the trigger, and released by the trigger.
Or the hammer/striker may be half-cocked by cycling the slide, then fully cocked and released by the trigger.
AND the same gun must have one or more of these single-action capabilities:
The hammer/striker may be fully cocked manually or by cycling the slide, then released by the trigger.
Or the hammer/striker may be half-cocked manually or by cycling the slide, then fully cocked and released by the trigger.

SA/DA (Single-action/Double-action) = The gun must have both of these capabilities:
If the slide has been cycled it fully cocks the hammer/striker, and the trigger's only job is to release the hammer/striker (SA).
Or if the slide has not been cycled the trigger will fully cock the hammer/striker and then release the hammer/striker (DA).

 

[rogerjames]

Thanks fellas, that helps a lot! I appreciate the willingness to teach those of us who are less informed/experienced but eager to learn. I hope to do the same as I become more proficient, and hope to bring some converts with me!

 

[possum]

rogerjames,
no problem bro that is what we are here for, and that is the same way we learned, just passing on the torch to everyone we can! have a good one!