What safeties do the M&P 2.0 have?

Drop safety is clear, what other safeties do they have?

Some have duel paddle type thumb safeties . Had them on a 2.0 long slide and didn't like them.

Sorry minus thumb safeties. I meant more internal safeties

Inertia safety on striker and trigger, plus sear engagement.
Your primary safety is to keep your finger off the trigger. Pulling the trigger releases all safeties and fires the round.
That's why I cringe when people want a 2# pull on a carry gun; when you're cold or excited, you may not feel your finger on the trigger.

So no trigger pull, no boom?

So where is the fault in lets say the P320? Why does the M&P (or other SF) not have that issue?

Gman686 said:

So no trigger pull, no boom?

So where is the fault in lets say the P320? Why does the M&P (or other SF) not have that issue?

Click to expand...

There are those who say it doesn't happen with the P320...

FWIU, nobody has yet proven the mechanism by which post-drop-safety recall P320s can 'go off.' The post recall guns got a lighter weight trigger shoe/blade to reduce inertia and a different sear (with more engagement, IIRC).

The P320 may have less margin for error with a damaged/worn/incorrectly manufactured part as it's a fully cocked striker design compared to the partially cocked strikers in Glocks and M&Ps. FWIU, that also applies to the PPQ/PDP and the VP9, but I haven't heard of any issues with those. They do, however, have trigger dingus safeties like most poly striker fire pistols. The trigger safeties aren't a complete guarantee; some aftermarket metal triggers have enough inertia to make them less drop safe than the factory polymer triggers. I saw a co-worker demonstrate that with a Glock trigger he installed for a guy.

Firing pin block that stops the striker unless the trigger is pulled. Both the hinged and flat faced triggers are designed so the trigger's inertia will not pull it back if the gun is dropped on to a hard surface.

The only reports of "accidental"/negligent discharges I have heard of with the M&P are the result of someone pulling the trigger on a loaded gun. Typical causes are having a finger or foreign object in the trigger guard when holstering the gun or dry fire practice with a gun that isn't as dry as the shooter thinks it is.

The most important safety, of course, is the one between your ears!

The issues with the P320? Well, there's still a lot of controversy about that. Someone puts their finger on the trigger, with no intention of squeezing it, and then the gun fires, 99.9% of the time they are going to claim that it "just went off!"

Gman686 said:

So no trigger pull, no boom?

So where is the fault in lets say the P320? Why does the M&P (or other SF) not have that issue?

Click to expand...

Who says they don't?

M&Ps blamed for accidental discharges | thefirearmblog.com

Saudade said:

Who says they don't?

M&Ps blamed for accidental discharges | thefirearmblog.com

Click to expand...

Indeed!

There were a lot of stories (and lawsuits) about negligent/accidental discharges in the 1990s as police departments switched from revolvers and semi-autos with long, heavy DA triggers to Glocks.

The DC Metropolitan PD had 120 accidental discharges from 1988 to 1998 after switching to Glocks. However, this overlapped with a 1989-1991 period of lowered hiring standards to fulfill a Congressional mandate to fill a shortage of 1,200 officers.

Apart from the optional thumb safety, I can think of the following automatic safety mechanisms in the M&P2.0:

1. Inertia firing pin which is shorter than its channel and held back by a spring so the pointed tip of the firing pin cannot touch the primer without the force required to overcome the firing pin spring.
2. Internal firing pin block to prevent inertial discharge if the weapon is dropped on the muzzle.
3. Trigger safety to prevent inertial discharge if the weapon is dropped on its rear.
4. Disconnector to prevent the weapon from firing out of battery.
5. Sear deactivation lever to permit disassembly without pulling the trigger.
6. If the prescribed method of disassembly is followed, the slide cannot be removed during disassembly without first locking the slide to the rear, which allows inspection of the chamber and which acts as a reminder to remove the magazine.
7. Slide cannot be removed forward off the gun without the magazine first being removed whether the slide is locked back or not.

I think that is all.

There are videos of it happening.

Pisgah said:

There are those who say it doesn't happen with the P320...

Click to expand...

OKFC05 said:

Inertia safety on striker and trigger, plus sear engagement.
Your primary safety is to keep your finger off the trigger. Pulling the trigger releases all safeties and fires the round.
That's why I cringe when people want a 2# pull on a carry gun; when you're cold or excited, you may not feel your finger on the trigger.

Click to expand...

Sometimes guns fire without a finger on the trigger or being dropped.
That’s why I like thumb safeties.

smoothshooter said:

Sometimes guns fire without a finger on the trigger or being dropped.

Click to expand...

True, but those are a vanishingly small percentage of all of the ADs/NDs.

shawn mccarver said:

Apart from the optional thumb safety, I can think of the following automatic safety mechanisms in the M&P2.0:

1. Inertia firing pin which is shorter than its channel and held back by a spring so the pointed tip of the firing pin cannot touch the primer without the force required to overcome the firing pin spring.
2. Internal firing pin block to prevent inertial discharge if the weapon is dropped on the muzzle.
3. Trigger safety to prevent inertial discharge if the weapon is dropped on its rear.
4. Disconnector to prevent the weapon from firing out of battery.
5. Sear deactivation lever to permit disassembly without pulling the trigger.
6. If the prescribed method of disassembly is followed, the slide cannot be removed during disassembly without first locking the slide to the rear, which allows inspection of the chamber and which acts as a reminder to remove the magazine.
7. Slide cannot be removed forward off the gun without the magazine first being removed whether the slide is locked back or not.

I think that is all.

Click to expand...

So you're pretty much saying with no trigger squeeze it's impossible for it to go off. Especially with the firing, ping block

Beju said:

FWIU, nobody has yet proven the mechanism by which post-drop-safety recall P320s can 'go off.' The post recall guns got a lighter weight trigger shoe/blade to reduce inertia and a different sear (with more engagement, IIRC).

The P320 may have less margin for error with a damaged/worn/incorrectly manufactured part as it's a fully cocked striker design compared to the partially cocked strikers in Glocks and M&Ps. FWIU, that also applies to the PPQ/PDP and the VP9, but I haven't heard of any issues with those. They do, however, have trigger dingus safeties like most poly striker fire pistols. The trigger safeties aren't a complete guarantee; some aftermarket metal triggers have enough inertia to make them less drop safe than the factory polymer triggers. I saw a co-worker demonstrate that with a Glock trigger he installed for a guy.

Click to expand...

M&Ps strikers aren't fully cocked?

Gman686 said:

So you're pretty much saying with no trigger squeeze it's impossible for it to go off. Especially with the firing, ping block

Click to expand...

The combination of the firing pin block (prevents inertial firing if dropped on the muzzle or receives a similar blow) and the tabbed trigger safety (prevents inertial firing if dropped on its rear or receives a similar blow) make it exceedingly unlikely assuming everything is in spec and working properly. Certainly, I have never heard of any M&P, whether 1.0 or 2.0, firing by itself.

I am not certain of your concern, and certainly, if you are aware of a case, I am sure everyone would like to hear about it.

Remember that an exceedingly large number of these pistols are kept fully loaded including a round in the chamber by countless law enforcement officers and ordinary citizens alike.

Gman686 said:

M&Ps strikers aren't fully cocked?

Click to expand...

In the M&P, it is my understanding that the striker is fully loaded or “cocked“ once a round has been chambered, and the only action caused by pulling the trigger is to disengage the firing pin safety and to release the sear causing the firing pin to fly forward. Most striker fired pistols have fully cocked strikers once a round is chambered.

The Glock, on the other hand, has only a partially loaded striker after chambering a round and as the trigger is pulled, the firing pin safety is deactivated and the striker is moved the rest of the way to the rear and when the striker reaches its full rearward travel, the striker clears the positive guide means allowing the connector to cause the sear to drop out of engagement with the lug of the firing pin releasing the firing pin so the firing pin can fly forward under spring pressure and fire the weapon.

If you look very, very carefully, at the M&P 1.0 sear/striker engagement, the factory sear has always appeared to cam the striker back. You'd need a dial indicator to measure the movement. Never struck me as an issue.

Curiousity aroused, I just put a frame in a vise and, the sear appears to cam the striker back. Not having a striker there to load the sear and the slide to limit possible vertical motion, the actual amount is a bit in question, but the sear does move the indicator backwards a repeatable amount. Getting exact data would require sacrificing a slide and the only folks really interested would be OCD nerds and liability attorneys.

While the amount isn't mechanically significant, if it's real, it does support a claim that the striker isn't fully cocked. Real world, does it really matter? Not really. Are the various aftermarket/2.0 sears different? No clue.

ETA: the gun went off when it shouldn't have issue. The swap over from revolvers caused the liability insurance carriers for law enforcement to drive the limitation of the term "accidental discharge" to those caused by mechanical failure of the firearm. Everything else is either negligent or unintended. Although there's another term being tried out, something like "uncommanded". Thanks Gaston!