Single or Double action?

[Rastoff]

The traditional definition of single or double action is based on the trigger and what it does. In a single action gun, the trigger only releases the hammer; one action. In a double action gun, the trigger cocks and releases the hammer; two actions.

Striker fired guns don't have a hammer, but they do have a sear. So, it is logical to see it as setting and releasing the sear.

The Glock trigger actually pushes the striker back a little as the trigger is pulled. Thus, I can see how it could be considered a double action only. The M&P however, only releases the sear. The striker/sear is set by the action of the slide. To me, since the trigger only does one thing, it's a single action.

To confuse things more, several of the M&P models are described as "double action only" on the S&W website.

So, which is the M&P? DA or SA? What do you think and why?

 

[Jayhawkhuntclub]

Neither, I would just call it a "striker fire trigger". But I'm fine will calling it a DA (even though it's technically not). Striker fired triggers don't feel anything like a true DA trigger IMO. And they sure don't feel like a SA trigger. Okay, maybe they feel like a really crappy SA trigger.

 

[Rgoodwin]

I think SA because pulling back the slide is similar to cocking the hammer.

 

[Bkreutz]

Single action because you can't pull the trigger a second time without racking the slide (Just MO)

 

[Tinn-Can]

I think they claim DA because of the hump on the sear... I ground mine off so does that make it SA?

 

[Rastoff]

I think they claim DA because of the hump on the sear... I ground mine off so does that make it SA?

What "hump" are you talking about? My sear has no such feature.

 

[ginzo]

I say SA because all the trigger does is release the striker, it doesn't reset it in any way.

 

[S&WForty]

To confuse things more, several of the M&P models are described as "double action only" on the S&W website.

That should read as follows:

To clarify things, several of the M&P models are described as "double action only" on the S&W website.

If it quacks like a DAO Glock...

/thread

 

[Tinn-Can]

What "hump" are you talking about? My sear has no such feature.

Then you don't have a factory sear? It is the little extra bit where the striker engages...

(Photo stolen from this sight)

 

[Rastoff]

OK, I see what you're talking about. Your definition of a "hump" and mine vary greatly.
"It's Frankensteen": Dr. Frederick Frankenstein meets Igor for the first time. - YouTube

Even so, that makes absolutely no difference to how the trigger works. Still only performs one function.

 

[George9]

I think SA because pulling back the slide is similar to cocking the hammer.

Pulling back the slide is not like cocking a hammer.. When the M&P goes to battery "this forward movement" of the slide that sets the striker. George

 

[Rastoff]

Pulling back the slide is not like cocking a hammer.. When the M&P goes to battery "this forward movement" of the slide that sets the striker. George

Cocking the hammer and moving the slide both set the sear. I see it as the same kind of action.

 

[Jayhawkhuntclub]

Pulling back the slide is not like cocking a hammer.. When the M&P goes to battery "this forward movement" of the slide that sets the striker. George

Huh?

 

[Rgoodwin]

Disagree George you can't push it fowward till you pull it back. Besides, I said similar.

 

[George9]

Cocking the hammer and moving the slide both set the sear. I see it as the same kind of action.

Yes I agree about the sear! But some don't seem to see that the striker is set or "cocked" only when the slide is in full battery from that forward movement of the slide. I myself consider it a S/A gun.. George

 

[George9]

Disagree George you can't push it fowward till you pull it back. Besides, I said similar.

Rgoodwin,
Sorry! Yes I agree we came to the same conclusion S/A!

 

[RichardDBeck]

Hammers and strikers do the same thing. They are spring loaded objects that store energy then transfer it into the primer. DA is when the trigger cocks the spring loaded object then releases that spring loaded object.

Single action is when the trigger is not capable of cocking the "spring loaded object". I would say because the trigger only performs a "single action" (releasing the sear) that the gun should be called single action.

 

[George9]

Well said! George

 

[Rgoodwin]

Agree 100 percent! Great explanation !

 

[Rgoodwin]

While we are on the trigger subject I gotta tell you guys what's happened with me and my FS 9. My trigger spring broke at the big hook. Sent S&W an email about two weeks ago very explicit about what part broke. I got an email back very quickly that said they would place it on back order. 6 weeks to get one. I stewed for a week and sent a response to their email which contains my email and all the particulars about what I need. Again they responded within 5 minutes that they shipped the part. Great, except today I get a package in the mail and its pretty big. I open it excitedly thinking hey they sent me a FS mag too. But no I'm frowning cause they sent me 2-15 round 40 mag springs instead. I've contacted them again. We'll see how this plays out. Sorry to hijack your thread just had to vent. Still love the brand just ready to be back in business.

 

[scattershot]

i voted single action, because the trigger only performs one function. On a M10 revolver, for example, the trigger performs two actions. Releasing the cocked hammer, or in a DA stroke, cocking the hammer and then releasing it.

 

[RichardDBeck]

I think they claim DA because of the hump on the sear... I ground mine off so does that make it SA?

I ground mine off as well. I would say it was always SA. I'm thinking that if you measure from the pivot point to the tip of the hump vs that same distance without hump the results are negligible.

I think the point was added to define a specific amount of surface area contact and not to further retract the striker during the trigger pull. I could be wrong about the intent...

Either way it requires a nice polish job anyways.

I think 99.98% pre-cocked vs 100% pre-cocked is not enough to claim DA.

 

[Don 73]

I see some votes for double action which I don't understand why.

The trigger ONLY lowers the sear in order to release the striker. The trigger does not reset (cock) the striker. Why would S&W even use the term double action for any m&p?

I can guess this one, the term "single action" can have a very negative affect on some people, who might think that single action and 'hair trigger' mean the same thing. The uninformed (including some police chiefs), think that single action and unsafe are terms that go together'

"double action" on the other hand is synonymous with a long, hard trigger pull, which some might take to mean that it is safer, less likely to go off by "accident."

 

[Rastoff]

Nicely said Don. Yes, I believe it's either legal or marketing reasoning for saying that they are Double Action only.

Of course, I find errors on websites all the time. It's entirely possible that whoever made the site was ignorant of what it means.

 

[Rgoodwin]

Much like the Senator who thinks magazines are only used one time and has a say so in new gun legislation!

 

[shawn mccarver]

I say M&P is DAO because ATF says so.

That said, it is more like a SA because pulling the trigger releases the cocked firing pin without pulling it further back before release as with the Glock. I believe the S&W is closer to the Springfield XD in that regard.

 

[Stratajema]

The biggest lie told by S&W is that their M&P pistols are double-action. They base this on the striker moving a micro inch backward during the trigger pull. Meanwhile, Springfield Armory pistols that use the same approach are labeled single-action.

Compare that to a true double-action striker-fired pistol, the Glock or Walther PPS that have a half-cocked striker prior to trigger pull.

 

[RichardDBeck]

Do glocks also use a striker block similiar to the m&p?

yes they do

 

[Der Biermeister]

I'm so confused ........

 

[Bkreutz]

I don't see the confusion. Take a double action auto and pull the trigger on a dead round, it doesn't go bang, if you pull the trigger again, it will hit the primer again and it may go bang (or not). Do the same thing with a M&P, what happens when you pull the trigger the second time..... nothing, you might as well wave your finger in the air. I see the reason for the long trigger travel in a M&P environment but to me the definition of a double action firearm is "self cocking" which means a full recock from being fired (or attempted firing). To me a microscopic rearward movement of the internals doesn't come close to what I would call a cocking action. I like my M&P a lot but wish it was a DA so that in the rare occasion that I get a failure to fire I could hit the primer again before racking it out on the ground.