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Post by taliyev on Feb 15, 2009 16:37:50 GMT -5
Gentlemen,
I am confused regarding type of action used in Kahr pistols. Based on what I know regardless of hammer or striker mechanism:
Single action gun : trigger pull drops hammer (or striker);
Double action gun : trigger pull cocks (action 1) and then drops
(action 2) hammer (or striker).
Now, according to all documentation and Kahr web site their pistols are "Trigger cocking DAO", but when I take unloaded K40 (or PM9), for example, and pull trigger, nothing happens unless I rack the slide. Then, if I pull trigger it drops striker, but sub-sequent trigger pull does not do anything... until slide is racked again.... This is the same behavior as 1911 or Glock , which are single action guns... Beretta 92FS, Walther P99 on the other hand are obvious double action guns (one hammer, one striker).
What am I missing? Why Kahr guns are labeled as DAO (double action only) ?
Thanks
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Post by TMan on Feb 16, 2009 3:31:59 GMT -5
Taliyev,
They are listed as DAO because they indeed do cock the gun before releasing the striker.
Striker fired pistols are a little different than most, and actually there are two different styles of them. Unfortunately, I don't have my Kahr in hand as I write this and I'm having to go by memory (what's left of it). Basically what happens is this:
Assume you have racked the slide. There is a little cam that is controlled by the trigger. As you pull the trigger the cam moves the striker backward and compresses the striker spring. As it continues to move backward, it starts to move downward, away from the striker. At some point it loses contact with the striker, allowing the striker to move forward; the firing pin hits the primer and the gun fires.
If the gun was empty, the slide never moved and where is the cam? It is behind the striker. You need to rack the slide in order to get the striker behind the cam. When the side is racked, the designer can determine how much pre-tension he wants on the striker spring. If you had a lot of tension, just a little bit of a pull would release the striker. The Glock does put a little pre-tension, but I don't remember the Kahr having very much.
So Kahr calls it a DAO pistol because like a conventional pistol having a hammer and sear, it does do the cocking motion prior to releasing the striker. Note that with a hammer and sear there is a true cocking. You can pull back the hammer so far, release it and the sear and hammer are at rest with the hammer being held by the sear. This is a true cocking. With this type of striker-fired pistols, they never really achieve a true cocking because there is continuous movement until the striker is released. (Yes, technically it will stop for a split-second as the direction is reversed, but it is never at rest).
I suppose you could call the state where the cam is capturing the striker "cocked", but if the gun was dropped and the striker released, there wouldn't be enough energy in the striker to fire the pistol. You impart the true cocking energy when you are pulling the trigger.
I hope this cleared it up somewhat. I'm not too sure how clear I'm thinking at this point. According to the clock, it is 4:30PM, but my body says it is 2:30AM. My wife is taking a nap, and one of her IT guys is here copying all her files to a new computer. If he wasn't here, I'd be taking a nap too.
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Post by taliyev on Feb 16, 2009 7:28:58 GMT -5
TMan, thank you for your response. I have looked at the action in motion shown on Kahr's web site and have observed operation as you have described it. While there is an obvious cocking there, it is not sufficient to re-strike misfired round in the chamber, so outside of longer trigger pull, this type of action has no real tactical advantages over single action mechanism.. At the moment I do not have Walther P99 in my hands, but I believe that it is striker based true DA gun... Am I wrong?
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Post by MLB on Feb 16, 2009 10:59:50 GMT -5
There are several versions of the P99, one is a SA/DA (the one I own is), and there is a DAO version as well. The P99 SA/DA trigger is confusing as well (there are 3 distinct trigger pulls on that one) but it does have a second strike capability. I'm pretty sure the DAO does too.
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Post by Callahan on Feb 16, 2009 15:10:48 GMT -5
Single action gun : trigger pull drops hammer (or striker); Double action gun : trigger pull cocks (action 1) and then drops (action 2) hammer (or striker).
Single-action pistol: Hammer must be manually cocked before the weapon will fire. (As in a old West style Colt single-action revolver or a 1911 that has a round in the chamber but the hammer is down with the safety on (not recommended method, but talking function here). The hammer must be manually cocked before the weapon can fire.
Double action pistol: In one continuous motion, the action of pulling the trigger draws back the hammer, cocking it, and the continued pull on the trigger then releases the hammer, firing the cartridge. (As in Smith & Wesson modern revolvers and SA/DA pistols such as Beretta and Sig. The hammer can also be locked back in single action and then fired with a lighter trigger than in DA. That covers the SA/DA category.
Striker-fired pistol: Chambering a round retracts the slide, pre-setting the striker. Pulling the trigger competes the action and fires, feeling much like a double-action trigger.Also, in tactical terms, many would argue the striker-fired pistols, such as Glock, are superior. This is especially true for civilians who are not highly trained. A 1911 carried with a round in the chamber and the hammer back, with the safety on (cocked and locked) requires the safety to be released before firing. That produes a magazine full of rounds that will be fired with a light trigger. Some say that's not a good situation for less than a highly trained handgunner. A DA/SA pistol give you a long, double-action trigger on the first shot, but then you must adjust to a lighter, single-action trigger for the rest of the magazine. A decocker safely lowers the trigger. A striker-fired pistol is basically like a double-action revolver. Long, consistent trigger pulls from start to finish and usually no safety to worry about. |
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Post by Callahan on Feb 16, 2009 15:18:51 GMT -5
There are several versions of the P99, one is a SA/DA (the one I own is), and there is a DAO version as well. The P99 SA/DA trigger is confusing as well (there are 3 distinct trigger pulls on that one) but it does have a second strike capability. I'm pretty sure the DAO does too. I'd like to see an explanation on the P99 DA/SA trigger sometime. That three-pull thing always confused me. I remember a member in the old forum (remember Mr. Bond?) who tried to explain it once. |
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Post by MLB on Feb 16, 2009 21:15:03 GMT -5
I do recall Mr. Bond. He was quite a fan of the P99.
Quickly, there's the traditional DA pull; long and hard(er). Cocking and releasing the striker.
There's the SA pull; light and short. The trigger is physically mostly pulled back, and just releasing the striker.
Then there's the "anti-stress". That's a long pull that has little resistance until the trigger reaches the SA position, after which the regular SA pull is felt. Just releasing the striker here too.
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Post by TMan on Feb 17, 2009 6:17:41 GMT -5
Sigh, I have to disagree with my fellow Texan (who probably isn't a Dallas Cowboys fan anyhow):
This is true for a lot of the striker-fired pistols like the Glock, Ruger SR-9, but it isn't true for a striker-fired pistol like the Springfield XD. The XD is basically the same type of action as the Mauser rifle. The XD is truely cocked and has a sear, when you pull the trigger, the sear moves out of the way and releases the striker.
I didn't realize this difference for quite awhile until I modified the XD. However, I should have known. The first time I shot an XD was immediately after shooting a Glock. I loved it, but didn't know why, other than the fact the trigger felt a lot better, and I got much better groups than I did with the Glock. I borrowed it for my CHL test, and bought one as soon as one became available.
I don't remember how the S&W M&P works.
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Post by Callahan on Feb 17, 2009 8:48:31 GMT -5
Sigh, I have to disagree with my fellow Texan (who probably isn't a Dallas Cowboys fan anyhow): This is true for a lot of the striker-fired pistols like the Glock, Ruger SR-9, but it isn't true for a striker-fired pistol like the Springfield XD. The XD is basically the same type of action as the Mauser rifle. The XD is truely cocked and has a sear, when you pull the trigger, the sear moves out of the way and releases the striker. I didn't realize this difference for quite awhile until I modified the XD. However, I should have known. The first time I shot an XD was immediately after shooting a Glock. I loved it, but didn't know why, other than the fact the trigger felt a lot better, and I got much better groups than I did with the Glock. I borrowed it for my CHL test, and bought one as soon as one became available. I don't remember how the S&W M&P works. Yeah, I figured the editors would come out of the woodwork on that one. I think my Walther has the Glock-like trigger, but not sure. I felt like we were beginning to mix apples and oranges, hence the reason for my post. I just don't think you can lump striker-fired pistols in with single action and double action guns. PS -- How could any person of good conscience be a Cowboys fan?  |
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Post by TMan on Feb 17, 2009 15:48:17 GMT -5
Good one!!!
Actually I'm a football sl*t. I ended up rooting for certain teams after getting to like players or coaches on those teams. This is all Bill Parcells fault. After what he did with the Giants, I became a Patriots fan, then a Jets fan, then a Cowboy's fan; and for some strange reason I sort of like the Dolphins now.
The Walther P99 trigger intrigues me, and I have no idea how it works. As I recall, I have the AS version, and I bought the gun because of the trigger action. If I ever get the time, I'll disassemble it to see how it works. First I have to get home and then get this massive interior remodelling effort done.
The packers were here on Monday and they packed 21 boxes. Where the heck am I going to put all that stuff when we get home? At least this 4 years of international assignments is over, and perhaps I can get a life back i.e. get back to my guns. ;D
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