"DA" Terminology Clarification

[Higgins]

What do you understand "DA" to mean:

A. Broad sense. It refers to the overall pistol function itself and means the pistol has two modes of operation - DA and SA (e.g. S&W Revolvers or Beretta 92FS) - that is, you can operated the pistol in so that the trigger both cocks and releases the hammer/striker and you can operate it so the trigger only releases the hammer, thus you have a double "mode" or trigger that can act in two modes. So, one could say, "It's a double action pistol because the trigger can be operated either as da or sa:" or

B. Narrower sense. It refers only to the operation of a trigger which both cocks and releases the hammer/striker when pulled. So, one would say, "It's a double action triggfer because the trigger both cocks and releases the hammer/striker." - without reference to whether or not a pistol can also be shot SA.

If the first case, then why label a pistol as DA/SA - wouldn't DA suffice? And how can Glocks, XD's, Steyr's be labeled DAO pistols if they have no SA mode? But if DA doesn't mean DA/SA, then why does, for instance, S&W identify it's DA/SA pistols as "Traditional Double Actions," which suggests a definition of "DA" ='s DA/SA.

I realize pistol terminology is a function of historical development and doesn't always follow rules of logic and even consistency. I just wondered others thoughts on this quandary.

My thought would be to limit the terms SA, DA et al. to the functioning of the trigger alone, and I would add a category - PA, or "pre-set action" trigger. Also, there would be no need for SAO or DAO terminology. So, you would have only SA, DA, PA and combinations thereof:

SA (or SAO) - e.g. 1911, BHP (Single Action Only trigger that only releases hammer/striker and in no way cocks it);

DA (or DAO) - e.g. FN49, Taurus 24/7, S&W Sigma (Double Action Only trigger that fully cocks and releases hammer, with no SA functioning);

DA/SA - e.g. Beretta 92FS, CZ75B (allows both of above trigger modes);

PA (or PAO) - e.g. Glock, Kahr, Steyr, Para LDA (slide action is required to preset the striker/hammer and the trigger only finishes the cocking then releases the hammer/striker, no provision for SA or DA operation)

PA/DA - e.g. HK P2000, Sig P226 DAK (same as above, but if slide doesn't preset the hammer/striker, then allows for DA second-strike operation)(C)opyright KWF

I'm sure some of you have opinions on all this, so let me have . . . er . . . hear it.

 

[Landric]

Well, the problem is that SA, DA, etc. refer only to the action that the trigger performs.

Double action means that the trigger both cocks and releases the hammer/striker.

Single action means that the trigger performs the single function of releasing the hammer/striker.

Double Action Only means that the weapon can only be fired in double action mode with the trigger performing the function of both cocking and releasing the hammer/striker.

When one refers to a double action handgun, be it semi-auto or revolver, one is refering to a handgun that can fire in either double or single action mode.

DA/SA/DAO do not refer to the number of different ways that a handgun can be fired, just the functions that the trigger performs.

Glocks, Kahrs, etc. are technically double action only because pulling the trigger brings the striker to "full cock" and then releases it.

 

[cruffler]

Wow. And I thought *I* was the only one who'd ever read "Armor!"

 

[SlimeDog]

Armor and Starship Troopers are, hands down, my two favorite Mil/SciFi novels. Great stuff!

 

[Jim Watson]

Well, Jeff Cooper says that what is now commonly called a DAO is really single action because it can only be operated in a single fashion. But usage has pretty much gone against him. The one I get tired of is TDA - Traditional Double Action, meaning Double Action First Shot, Single Action Thereafter. I'd rather DA/SA for those. But we don't get to make up definitions; that is left to the advertising agencies and magazine writers.

I didn't think Armor was up to Starship Troopers. And Steakley is certainly no Robert Heinlien.

 

[carpettbaggerr]

If you want really good military sci-fi, check out Lois McMasters Bujold's series about Miles Vorkosigan.

I think the plasma arcs are double action, and the nerve disruptors are single action.

 

[Jim Watson]

Man, I'd WANT a New York trigger on a plasma arc.

I once went 'round and 'round with David Drake re cupro-nickel bullet jackets in The Chosen.

 

[mondocomputerman]

So Double action doesn't mean a double tap? Haha

 

[Dave T]

So Double action doesn't mean a double tap? Haha

Actually, with the DA/SA described here it often does. I have seen numerous students (beginners) struggle with the first long hard pull of a DA/SA semiauto only to have the second (much lighter and shorter) SA pull go off inadvertently. Result: the so called "double tap" from a "double action".

 

[faustulus]

A DA to me is just what the name implies, a gun whose trigger performs two actions cocking and releasing the hammer. After the first shot is performs only one action, but it is capable of performing two. So in that sense most traditional guns are double action.
A SA gun only releases the hammer, it can only preform a single action.
A DAO gun performs two actions (cocking and releasing the hammer/striker) all the time.

 

[BrokenArrow]

As usual, the confusion is between what the trigger does and how many ways you can fire the weapon.

The Walther P99 can be fired three ways, one double action mode and two single action modes, so I guess that makes it a triple action (TA) pistol?

The feds (BATF and NIJ) are the official decision maker; gun X is what they say it is. The XD is SA and the Glock is DAO, even though they feel about the same to your finger and each can only be fired that single way...

The NIJ (National Institute of Justice) uses another term: SFA (Striker Fired Action). A SFA could be DAO (Glock), or SA (XD), or both (Walther).