"Single action" and "double action"--history of these definitions?

[Herknav]

I always thought that these terms referred to how many actions, or steps in the firing process, a shooter could perform with one trigger pull. In other words, a "single action" trigger could only do one thing--drop the hammer. Conversely, a double action trigger could do two things--cock the hammer and release it.

Imagine my surprise when I was reading Jeff Coopers' "Fighting Handguns." In his double action chapter he says that under the strict sense of the definitions, these terms refer to how many ways the gun can be fired. To wit, a "single action" could only be fired one way--by cocking the hammer (e.g. the Colt Peacemaker), and a "double action" could be fired either by either choosing to cock the hammer first or not. Interestingly enough, if you take Lt Col Cooper's definitions to heart, what we call a DAO is actually a "single action" because it can only be fired one way.

I realize the language changes over time, and this book was written many moons ago. I was just curious if any of you could fill in how these terms have changed over the intervening years.

Thanks,
Herk

[alfsauve]

I think originally, no "facts" to back this up, just gut feel, that DA meant it could fire SA and fire by having the trigger cock the hammer.   

But then things got confusing.  DAO meant it could cock and fire with a trigger pull but not SA.

Then things got more confusing as the current crop of semi-autos, which are partially cocked and you finish the cocking by pulling the trigger.   They're not true SA, but I don't think they should be called  DAO either, since you can't fire them if they aren't partially cocked.  (Dry fire any of the current crop of DAO guns, then without operating the slide try to dry fire it again.  Only a few will pass the test.)     I think we need a new term.   Something like PDA for Partial Double Action.  Or Semi-Double Action Only.

[Solus]

Well, on this one, I'd say Col. Cooper was wrong.

If you take a standard double action revolver and shroud the hammer or remove the hammer spur does it become a single action?  I don't think that is what this description needs to convey.

My thinking would be that the shrouded or bobbed hammer models become DAO.

About the autos that need the slide to cycle to partially cock the striker, I guess we call them Single and a Half Action 

[tt11758]

I care less about what we call them than I do about making sure we have access to them.

[Timothy]

Pull trigger, goes bang!     Two actions, one result...

This conversation will continue but firearms are changing.  Mechanisms were simpler when the original action discussion started.  Today, not so much.

Someday we will have "fire by wire" handguns that will text message the intended victim that they are about to die...

 

[Sponsor]

[MikeBjerum]

I have read a lot on gun terminology over the years and did a little more reading this morning, and I can not find anything to support Col. Cooper other than his own writings.

I have to go along with Solus on this one, and I will stay with the "traditional" definitions we have used for years:  How many steps can the trigger perform and how many steps does the trigger perform (drop hammer only, cock and drop hammer or double action fired single action)?  To add more classifications would just muddy the world of defining firearm actions ... However, the over educated have been doing this for years in many other areas of our lives  

[MikeBjerum]

Pull trigger, goes bang!     Two actions, one result...

This conversation will continue but firearms are changing.  Mechanisms were simpler when the original action discussion started.  Today, not so much.

Someday we will have "fire by wire" handguns that will text message the intended victim that they are about to die...

 

Did I fire five or did I fire six ... You know, in all the excitement I don't know ... Do you feel lucky 

It's a text you know, so don't forget to add the little emotions ...  how about  sent out in a fifty yard radius when the safety is clicked off