Terminology debate...SA/DA and the realities of LDA

[Playboypenguin]

I have talked about this topic with a few people in the past couple weeks and I thought I would make it a public discussion.

I have always thought that LDA (Light Double Action) pistols are kind of a misnomer...as well as some proclaimed to be DAO like Kahr.

I consider them to be more long pull SA than I do DA of any type.

My reasoning is that to be DA in my mind the trigger has to be able to not only release the firing mechanism but to also put it into a position where it can be fired. The LDA pistols (and the DAO's like Kahr) fail to do this since they cannot fire without first racking the slide. The also cannot fire again in the case of a misfire.

I just think that if all the trigger does is press back the hammer/pin enough for a sear or other block to be pulled away or just pull it away directly then release the firing pin/hammer it is not really doing anything to place the gun in a fireable mode. It is just disengaging a safety of sorts.

I think a more appropriate name for this type of trigger would be SSA (Safe Single Action) or maybe LPSA (Long Pull Single Action).

I sometimes think gun manufacturers just stick to the "Double Action" name because of the false sense of safety it brings with it for some people.

Anyone agree? Disagree? Not care? Think I should get a life?

 

[Shadi Khalil]

I know what you mean. It definetly feels like a long single action. Infact, in the absents of a grip saftey i would never carry one of those. I wouldnt say the same about my sig or the karh mk9 I owned in the past (god i miss her ) As far as you getting a life, If that interferes with your OCGBD (obsessive compulsive gun buying disorder) I'm against it.

 

[Officer's Match]

I agree: DO NOT GET A LIFE.

 

[HammerBite]

I sort of agree with PP. Pulling the trigger draws the hammer back so that the cocking cam can drive it forward again. In that respect it behaves like a DA. On the other hand, the cocking cam must have been already cocked and at the end of the trigger stroke the cocking cam is released. In that respect it behaves like a SA.

The beast is neither fish nor foul, and Light Double Action is probably as good a name as any.

 

[SKM&P9]

I'm afraid I have to second the vote with Officer's Match PBP. DO NOT get a life as you say, but rather, continue to purchase all kinds of handguns, preferably the stainless variety you seem to prefer, and please continue to post the pics for us to see ! Your photography skills seem to improve with each new purchase !

 

[JohnKSa]

Para's LDA is pretty unusual, I can only think of one other gun offhand that has a similar action (Daewoo DP51). I agree that DA is a misnomer since the trigger doesn't really have anything to do with cocking the gun. The slide cocks the "internal hammer", the trigger only moves the "external hammer" around and trips the "internal hammer".

On the other hand, the Kahr/Glock type operation is a bit more complicated. The slide has to be operated for the trigger bar to pick up the striker, and the action of the slide also puts some tension on the striker spring (does some of the cocking work) but then the trigger must complete the cocking stroke and drop the striker. So there are some DA aspects to the gun and some SA aspects. I think that DA is less of a misnomer but people who think a Glock or a Kahr is a true DAO will be disappointed to find that the trigger won't do anything if the slide isn't operated first.

 

[Jim Watson]

I think the mechanical design has outrun the terminology, but I also think it will be difficult to make up new names for the new actions and get them widely accepted.
Me?
I know at least generally what is going on in most of the readily available pistols. Tell me you have a Kahr and I know what you are working with. I even follow some of the advertising agency drivel, like LDA, DAK, and LEM. If it is something new on me, I will ask for explanation.

 

[Playboypenguin]

people who think a Glock or a Kahr is a true DAO will be disappointed to find that the trigger won't do anything if the slide isn't operated first.

Correct...I am not saying I would rather my Kahr be a true DA, like my Seecamp or NAA Guardian, but it is a bit of a surprise to find that in reality it does not function as a DA at all.

 

[JohnKSa]

I think the mechanical design has outrun the terminology, but I also think it will be difficult to make up new names for the new actions and get them widely accepted.

Partly because gun companies are coming up with patented names for them.

Probably the best name I've seen for the Glock/Kahr type action is "Hybrid DA".

I don't know if Daewoo patented the "Fast Action" moniker, but even if they didn't, it's not very descriptive. "LDA" is a misnomer, as discussed. The best I can come up with would be "External/Internal Hammer Hybrid Action" which is pretty lame.

 

[Jim Watson]

"Fast Action" is a FN/Browning trademark. They offered guns with the "push it forward so it doesn't look dangerous" hammer in the Army trials of the 1980s. The gadgets for that are now made as the Safe Action System retrofit.

The Daewoo is "Triple Action."

 

[JohnKSa]

I didn't know that. I saw the DP51 referred to as Fast Action several times in print and assumed that it was their term. I didn't know about the earlier Brownings.

 

[HammerBite]

Summary of Hammer Forward Cocking Systems

Some people have an aversion to cocked-and-locked carry but still want to be able to quickly fire the gun with a light pull of the trigger. Fulfillment of this desire entails three requirements:

• The gun must be carried with the hammer forward.
• It must be possible to fire the gun without manually cocking the hammer or racking the slide.
• A standard double-action mechanism, with its heavy trigger pull, cannot be used. A light trigger pull is needed.

A general scheme for meeting these requirements follows:

• The hammer is not directly driven by the mainspring.
• Within the body of the hammer, rotating on the same hammer pivot, is a driving device which is powered by the mainspring and is caught by the sear when the gun is cocked.
• The hammer and the driving device move semi-independently: The hammer, when rotated back, rotates the driving device. The hammer may then be rotated forward, leaving the driving device cocked. The driving device, when released by the sear and rotated forward under the impetus of the mainspring, rotates the hammer if the hammer was back.

I know of three currently available embodiments of the above scheme:

• R.D.I.H. Safety Fast Shooting (SFS) system: Imported and distributed by Cylinder & Slide for the Colt M1911 and the Browning HP. The driving device is called the "hammer ring" in this system.
• Para-Ordnance Light Double Action (LDA) system: The driving device is called the "cocking cam" in this system.
• Daewoo Fast Action system: Implemented in the DP-51 and the DH-40. The driving device is called the "hammer cam" in this system.

R.D.I.H. SFS

When the hammer is rotated back it rotates the hammer ring with it. The hammer ring is caught by the sear. The hammer is held in the rearward position by a light spring.

When the hammer is then pushed forward it is latched in that position and the mechanism automatically applies the thumb safety. When the thumb safety is subsequently moved to the "off" position the hammer is unlatched and springs back to the rearward position.

When the hammer is in the rearward position and the trigger is pulled, the sear releases the hammer ring, which rotates forward under the impetus of the mainspring. The hammer is driven into the firing pin by the hammer ring.


Para-Ordnance LDA

When the hammer is rotated back it rotates the cocking cam with it. The cocking cam is caught by the sear. When the rearward force is removed from the hammer it is returned to the forward position by a light spring.

When the trigger is pulled the drawbar rotates the hammer to the rear. At the end of the trigger stroke the drawbar raises the sear and the cocking cam rotates forward under the impetus of the mainspring. The hammer is driven into the firing pin by the cocking cam.


Daewoo Fast Action

When the hammer is rotated back it rotates the hammer cam with it. The hammer cam is caught by the sear. When the rearward force is removed from the hammer it is held back by a spring-loaded detent. When the hammer is then pushed forward the hammer is held forward by a spring-loaded detent.

When the trigger is pulled the drawbar rotates the hammer, if forward, to the rear. At the end of the trigger stroke the drawbar raises the sear and the hammer cam rotates forward under the impetus of the mainspring. The hammer is driven into the firing pin by the hammer cam.


U.S. Patents (for those who want to know the nitty-gritty)

• 6,539,658 -- Leon & Robert Hubert. Assigned to R.D.I.H.
• 6,381,892 -- Atilla Szabo & Borislav Vulanovic. Note that Szabo was the president of Para-Ordnance.
• 5,166,458 -- Dae-Soon Yoo. Assigned to Daewoo Precision Ind., Ltd.

 

[Tamara]

...leaving the driving device cocked.

Which is why a Para LDA is no more "Double Action" than is a Ruger Blackhawk.

 

[Playboypenguin]

Which is why a Para LDA is no more "Double Action" than is a Ruger Blackhaw

Yeah...and what is the deal with the fake external hammer???

 

[Tamara]

...and what is the deal with the fake external hammer???

Oh, that's a real hammer. It really hits the firing pin and the gun really won't work without it.

Read the post by "HammerBite". Detail strip your weapon. You'll see how the moving bits interact.

 

[Playboypenguin]

Oh, that's a real hammer. It really hits the firing pin and the gun really won't work without it.

Are you sure?

When I look at the diagram of the gun it does not appear possible that the external hammer actually makes contact with the firing mechanism.

Plus, a guy that goes to my range has one that the rear hammer stopped functioning properly on but it would still fire. The external hammer would barely move when the trigger was pulled due to a bad spring or something. Para sent him a new spring which fixed the issue.

 

[Tamara]

Are you sure?

One-hundred percent positive. I am more sure that the LDA's hammer is a real part of the firing mechanism than I am that the sun will rise today, since I have taken apart an LDA, but the sun has a couple of hours left in which it could blow up.

Plus, a guy that goes to my range has one that the rear hammer stopped functioning properly on but it would still fire.

To put it politely, either he lied to you or you are lying to me. The only way can see that it could "stop functioning" and the gun still fire is if it simply remained to the rear after firing, although I am open to correction by a 'smith with more time in the guts of an LDA.

Look, don't take my word for it: Detail strip your firearm and see what makes it tick. Look at the fricken' patent drawings that "HammerBite" so courteously provided a link for.

 

[Playboypenguin]

Look, don't take my word for it: Detail strip your firearm and see what makes it tick.

I don't have one.

All my knowledge of the firearm comes solely from his and what I have looked up online after being intrigued by what he told me about it.

...and what I read on another firearms board from Larry Seecamp who designed the system used by Kahr. he also claims the hammer is purely cosmetic.

either he lied to you or you are lying to me.

I am keeping this a civil discussion and phrased my reponses in uncertain tones. I did not make any definite challenges to you are what you said. I think the accusations of lying are a bit out of line.

 

[Tamara]

The system used by Kahr is a striker-operated system. The LDA is a different kettle of fish entirely.

he also claims the hammer is purely cosmetic.

I can't imagine Larry Seecamp saying that. Link?

Unless he said that the hammer spur was purely cosmetic, which it is. A hammer spur on a hammer you can't cock is about as useful as a kickstand on a tank.


RE: The lying comment. Yes, it was harsh, but you just told me that you knew of some guy at the range whose gun was doing something that it couldn't possibly do. If I said to you "Hey, Playboypenguin, I know a guy at the range whose Rorbaugh feeds .45ACP from Glock magazines," what would you call that?

 

[Playboypenguin]

Are you saying that the external hammer somehow releases an already cocked internal firing mechanism by striking it?

If I remember correctly, his would pull the rear hammer and release it every time you pulled the trigger but the gun would not fire unless it had first been cocked by the slide.