Striker Fired and DA vs SA - M&P?

[HoosierQ]

There seem to be a lot of different actions on striker fired pistols. S&W Sigma is pretty much 100% DA, Glock is 70% DA. All this is based on the amount of travel of the striker when the trigger is pulled and/or the ability of the striker to pop the primer from an "at rest" position...

...I guess. This is where my question comes in. Another THR member FlaChef had a small chart (and noted some of the things I mentioned above)

So, is there a definitive way to know whether your striker fired pistol is DA or SA? Is there and industry standard? Heaven forbid a regulatory standard?

Is the XD really a full SA pistol?

What is the M&P, DA or SA?

At any rate, anything that educates me and others on striker fired pistols would be great! Oh for the straightforwardness of the hammer!

 

[TG13]

the XD is SAO..

the M&P is DAO according to S&W..

 

[MachIVshooter]

Most striker fired pistols are more SA than DA. Glock, XD, M&P will not reset the striker simply by pulling the trigger. Like a true SA pistol with an enclosed hammer, you must rack the slide to reset the striker.

the newer Taurus pistols do actually go true DA if the SA mode fails to detonate a primer.

 

[jocko]

I would say the M & P is really striker fired single action. Pulling that trgieer is certainly not cocking the striker..

 

[Runningman]

M&P and Glock are single action design no mater what liability lawyers want to call them. If you get a dud, pull the trigger a second time and you will see that you get nothing. Hence a single action

Or you can test it with NO Round in the chamber. With the gun UNLOADED ........both chamber and magazine! At a range with the gun pointed in a safe direction. Rack the slide once only, than fire it. Now pull the trigger again without racking the slide. You will not hear the firing pin drop on the second pull. Hence a single action.

Now on a DA/SA type semi auto pistol a second pull of the trigger on a dud will cock and drop the firing pin again sort of a 2nd chance at firing the primer.

 

[Top_Gunn]

We need better terminology. Everybody knows what "double action" means in a revolver. No DA autoloader does what a DA revolver does (advance to the next cartridge and fire it). A Glock resembles DA in the sense that the trigger pull cocks the striker fully on every shot, but, as others have noted, there's no second-strike capability and you do have to rack the slide before you can fire it. So, from the point of view of what you have to do to make it work, a Glock is SA.

 

[SSN Vet]

not any kind of expert here.... but I do like to ramble...

The term single action seems to have it's origin rooted in firearms that utilize a spring loaded hammer to strike the firing pin (both revolvers and autoloaders). On a single action model (i.e. 1911), you have to cock the hammer, either by racking the slide or pulling the hammer back with your thumb. Then the trigger only performs a single action... as it acts to trip the sear and release the hammer.

Double action implies that the trigger does two operations. Both cocking and releasing the hammer. But as mentioned, a DA revolver also advances the cylinder, hence loading the next round.

With modern striker fired weapons, the striker is held back under spring tension and then tripped. On a single action stiker fired pistol, (i.e. XD), the stiker is "cocked" by racking the slide and the trigger performs the single action of tripping the striker. Carrying around a SA striker fired pistol with a round in the pipe and the stiker cocked is precarious to say the least, so a manual safety is considered necessary.

On a double action striker fired pistol (i.e. Keltec) the trigger both cocks and releases the striker. Since you have a longer trigger pull that requires substantially more force, the manual trigger is considered optional.

On DA/SA hammer fired pistols (i.e. M9) the ready condition for the pistol has a bullet in the pipe and the hammer NOT cocked (hence the de-cocking mechanism). The first trigger pull cocks and releases the hammer. After the first round is fired, the slide racks under recoil, both chambering the next round and cocking the hammer. So the next trigger pull simply trips the sear and releases the hammer.

I believe Glock calls their mechanism "safety action". Here the stiker is mostly cocked by the racking of the slide and the trigger pull both finishes the striker cock and releases the striker. This partially cocked striker, along with the other safety features like the trigger switch thingy, is how they get away with not having a manual safety.

On the new Taurus mechanism, you basically have a single action striker fired pistol, but if you have a failure to fire (no cycling of the slide under recoil) the trigger mechanism will both cock and release the striker, for a "second tap" capability.

Just to confuse things, modern DAO trigger mechanisms (i.e. Kahr) can be just about as smooth and light as some stiffer SA mechanisms. But a match grade trigger in a SA pistol or a nice trigger job on a SA revolver will give you the very best trigger pull of any option out there.

 

[jocko]

I think the glocks actually do pull back the striker somewhat, maybe 50%, not sure I would call that a single action. Now the Smith M & P, that puppy is basically cocked and locked, pulling the trigger basically doesn't cock any more of the striker but merely unblocks it for ignition. I stand corrected if that is wrong..

Probably could argue this as is the glass half full or half empty...

 

[gglass]

If a company wants to be considered for a majority of Defense department and civilian LE agency sidearm bids, they will have to list the weapon is DA / DAO.

The current body of wisdom with regard to trigger action is that DA / DAO makes a safer carry weapon. Namely, the gun does not go bang unless somebody intentionally pulls the trigger. Most striker fired pistols are technically a Single Action, but as long as the striker is being moved in that action, the manufacturer can call it a DA or DAO firearm. In the civilian world, it is easier to sell a handgun when it's advertised as SA, but those government contracts are just too lucrative for the manufacturer to be 100% accurate.

Welcome to the fuzzy world of government appropriations.

The biggest reason that Springfiled XD's are picking up government and civilian LE contracts is that they are listed as SAO.

 

[gc70]

Just to muddy the waters of striker-fired guns, here are a couple more variations to consider.

Walther P99 / S&W SW99
Striker-fired DA/SA variants with true second-strike capability.

HK P7
A really oddball design, with an SA trigger, but the state of the stiker depends on whether or not the grip is squeezed. Squeeze the grip and the striker is fully cocked; release the grip pressure and the striker is fully uncocked. Second-strike capability is available by releasing and re-squeezing the grip.

 

[9mmepiphany]

i happen to like the 2nd strike capability. my choices would be the:

1. HK P-7...just about the safest pistol out there as it decocks if you happen to drop it and is the most accurate
2. Walther P-99...great ergos, but long DA trigger stroke

if you don't need the 2nd strike capability, i'd choose the XD...because of it's ambi design