CZ-75 SP-01 External safety vs decocker

[TunnelRat]

Most modern gun designs have firing pin blocks, and all such weapons safe if dropped -- and it matters not whether a safety is engaged or not.

A firing pin block will not stop the firing pin from moving if momentum drives the trigger to the rear from an impact. The tab on the Glock trigger is an additional preventative measure in that regard. There's also the drop safety activated by the trigger bar that holds the striker in place until the trigger is pulled (similar to the spring holding the firing pin on a hammer fired pistol, so that might be a wash though you could argue the shelf offers more resistance than a spring). I seem to remember people saying that with a Glock, since the trigger travel finishes cocking the striker, it also doesn't have enough force in the striker to ignite a primer until the trigger stroke is finished (not 100% sure on that). You can argue that all of these in combination with the firing pin safety/block are redundant and that may well be, but I'd say at least theoretically there is more to stop an unintended discharge than a cocked hammer fired pistol with no safety.

Fun propaganda.
https://us.glock.com/technology/safe-action

 

[Walt Sherrill]

A firing pin block will not stop the firing pin from moving if momentum drives the trigger to the rear from an impact.

Can you cite some examples where that has actually happened with any FPB-equipped SA, DAO, or DA/SA in a real life accident, or when such a gun was tested?

The momentum created by dropping a gun on it's muzzle arguably moves things FORWARD not REARWARD.

In hammer-fired gun designs that use a pivoting trigger, the trigger bar/connector (not the trigger) would have to move forward, but can do so only by overcoming several different types of spring pressures (trigger, firing pin block, sear, and hammer) before the FPB can be deactivated.

Variations of the 1911 (Series 80? and 1991) and other SA hammer-fired designs have internal mechanisms that must also be moved to the rear to deactivate the FPB. For many of these guns, the parts that must be moved to the rear are already forward and the momentum of a drop keeps them there except, perhaps, for a brief bounce.

In all of these designs, deactivation of the FPB requires both the proper, full trigger (or trigger bar/connector) travel and proper timing; if the various parts don't work together just right -- as might not happen with a drop --the firing pin block remains engaged! Most of these mechanisms are surprisingly simple but amazingly robust.

The state of California has done extensive testing of many, many different FPB-equipped guns, and those guns use a variety of firing pin block designs. The potential problem you describe above is a bit like the mythical unicorn, it may exist but it's not often seen...

 

[Limnophile]

We've been over this before.

And we'll keep going over it until you get it.

A Glock is notably more drop safe than a cocked SA pistol with no safety.

I don't think this is true for a stock CZ 75 SP-01. As Walt points out, all current CZ 75 variants (certain customized versions and the CZ 85 Combat excluded) have firing pin blocks (FPBs) that make them drop safe. Note the notch in the CZ 75 B firing pin:

http://i110.photobucket.com/albums/n87/Dosmilman/cz75partsni6.jpg.

The FPB resides in that notch until the trigger is fully depressed and thus lifts it, which makes it impossible for the firing pin to move forward to strike a primer. As I recall, you have a CZ 75 P-01, which is a B variant. Field strip it, remove the firing pin, and examine how it interacts with the FPB. That should allay your concern. Then examine your firing pin spring. The firing pin is inertial -- it does not protrude outside the slide. In the absence of a FPB the spring is strong enough to prevent the firing pin from moving forward with enough force to cause a primer detonation in the event of a reasonable worst-case drop (define by CA law as striking muzzle first from a height of 3 ft, as I recall). I recall reading that Angus Hobdell of CZ Custom tried to get an 85 Combat trigger to actuate upon dropping from atop a ladder without success.

The only incident I know of where a FPB failed was when a law enforcement officer entered an MRI suite for an exam holding his Colt 1991. The huge MRI magnet ripped his gun from his hand, and the gun discharged upon slamming into the machine, despite the safety lock being engaged. The magnet obviously lifted the FPB so that the violent impact overcame the force of the firing pin spring to drive the pin forward with enough energy to cause the AD.

I was hesitant to adopt cocked and locked carry when I got my first CZ. I carried a couple of days with the gun unloaded just to assure myself that the safety would remain engaged. I became more confident after examining how the drop safeties worked. Upon coming home I unholster my gun and examine it before putting it away. Only once has the safety been deactivated. Whether that was because I forgot to safe the gun before holstering (the most likely explanation), or if the safety somehow was deactivated during carry, it did not bother me, because I understand the internal safety mechanisms kept the holstered gun perfectly safe regardless. However, I continue to engage the safety lock before holstering, and I continue to shun Glocks.

For that matter it also typically has a heavier trigger pull.

The stock SA trigger pull on DA/SA CZ 75 variants is nominally 6 lbs, which is roughly equivalent to the stock trigger pull for a Glock (nominally 5.5 lb). If and when I get around to sending my CZ 75 Compact to CGW, it will return with a DA trigger pull of about 6 lb and a SA trigger pull of about 3.5 lb. I understand a common refinement of a Glock trigger yields a 3.5-lb pull. Comparing apples to apples trigger pull differences become moot.

There's also the liability of carrying a pistol in a manner not intended by the manufacturer.

I agree it's generally wise to follow the manufacturer's precautions, yet I carry my .380 Auto CZ 83 magazines with 13 rounds instead of the Instruction Manual saying to load no more than 12, and I routinely insert Q-Tips into my ear canals despite Johnson & Johnson vehemently saying not to do so.

But, I agree that it is unwise to carry any CZ 75 variant cocked and unlocked, and I will not encourage anyone to do so. But, I won't allow that to stop me from stating the fact that cocked and unlocked carry of a CZ is functionally equivalent to Glock carry. I interpret this valid comparison somewhat differently than you do.

You're letting your fervor to defend cocked and locked carry drive you to make both inaccurate and unsafe statements.

I am guilty of being a proponent of cocked and locked carry. This forum is chock full of inaccuracies, and I'm sure I've contributed to them once in a while. But, the burden is on you to prove that anything I've said in this thread is untrue, and you have not come close to doing so.

Despite being a fan of Condition 1 carry, I would recommend a handgun without an affirmative external safety to a person who's first firearm is a defensive handgun. But, I would recommend such gun be DA/SA or DAO with a long, heavy DA trigger pull, which is in effect a proven safety mechanism.

To the points that have been brought up, with dedicated training either system can work. If you can train enough to master a DA pull then you can train to remember a safety (not to mention the safeties already on carbines and shotguns that people use for defense).

Agreed.

I've grown tired of people telling each other here what will and won't work for others. With any system there are training concerns. Be sure to address them and choose what works best for you.

Choosing is a matter of preference, and preference is not debatable. But, the merits and pitfalls of the two systems -- external affirmative safety vs no such safety -- are typically not fairly represented.

 

[Pilot]

I have several CZ-75 variants, and prefer the safety versions. The only decocker I have is the 75D PCR. It is such an excellent all around pistol, I overlook that is a decocker.

 

[TunnelRat]

Can you cite some examples where that has actually happened with any FPB-equipped SA, DAO, or DA/SA in a real life accident, or when such a gun was tested?

The momentum created by dropping a gun on it's muzzle arguably moves things FORWARD not REARWARD.

In hammer-fired gun designs that use a pivoting trigger, the trigger bar/connector (not the trigger) would have to move forward, but can do so only by overcoming several different types of spring pressures (trigger, firing pin block, sear, and hammer) before the FPB can be deactivated.

Variations of the 1911 (Series 80? and 1991) and other SA hammer-fired designs have internal mechanisms that must also be moved to the rear to deactivate the FPB. For many of these guns, the parts that must be moved to the rear are already forward and the momentum of a drop keeps them there except, perhaps, for a brief bounce.

In all of these designs, deactivation of the FPB requires both the proper, full trigger (or trigger bar/connector) travel and proper timing; if the various parts don't work together just right -- as might not happen with a drop --the firing pin block remains engaged! Most of these mechanisms are surprisingly simple but amazingly robust.

The state of California has done extensive testing of many, many different FPB-equipped guns, and those guns use a variety of firing pin block designs. The potential problem you describe above is a bit like the mythical unicorn, it may exist but it's not often seen...

What if the pistol doesn't land on its muzzle but on the rear of the slide and grip?

If your argument is that the likelihood of what I'm describing is next to impossible to happen, then I agree. That doesn't, however, mean that the Glock does not have more internal mechanisms to prevent an accidental discharge from a drop than a hammer fired pistol cocked but with the safety disengaged.

 

[TunnelRat]

I agree it's generally wise to follow the manufacturer's precautions, yet I carry my .380 Auto CZ 83 magazines with 13 rounds instead of the Instruction Manual saying to load no more than 12, and I routinely insert Q-Tips into my ear canals despite Johnson & Johnson vehemently saying not to do so.

If you think those acts bear the same safety risk as carrying a pistol in a condition not prescribed by the manufacturer then I see no point in engaging in further discussion with you.

I interpret this valid comparison somewhat differently than you do.

Agreed. I don't interpret it as valid. I know that you do. We're at odds on this and I don't see that changing.

And we'll keep going over it until you get it.

We won't. I have no desire to rehash this with you when it's been gone over ad nauseum in previous threads. I made the mistake of responding to you again in this thread. I will refrain from doing so in the future, if for no other reason than it leads to topic drift (this thread isn't about Glocks). Best of luck in your shooting endeavors.

 

[Limnophile]

If you think those acts bear the same safety risk as carrying a pistol in a condition not prescribed by the manufacturer then I see no point in engaging in further discussion with you.

Nice straw man.

I hear you saying you are unable to refute my claim that carrying a CZ 75 cocked and unlocked is any less safe than carrying a Glock. Both require only a nominal trigger pressure of 6 lb to fire, and both meet CA drop safety standards.

 

[sigarms228]

No matter how much time one puts into mastering the DA trigger pull, one's SAO groups will, on average, always be tighter than one's DAO groups from that particular DA/SA pistol. It's physics.

If one is truly concerned about one's inability to train to deactivate the safety when bringing the pistol on target (is there any evidence that anyone has ever lost a DGU because of this?), one can always carry in Glock mode -- cocked and unlocked.

At 25 feet in SA I can group about 1.5 inches 10 shots. In DA that is about 3 inches with many of those concentrated in smaller group.

If i am shooting at someone in my house it will almost surely be at distances less then that and my DA accuracy is plenty good to hit in the vital zones.

However my main concern is safety and NOT discharging my pistol when I do not intend to. DA long and heavy trigger pull gives me extra margin of safety in a situation where I have just awoke from deep sleep and adrenaline dump kicks in. No one knows for sure how their training will hold up in such situations. Those who have observed those in such situations have seen a large percentage of trained shooters with their finger on the trigger before they ever intended to shoot.

In the end do whatever you are comfortable with. For me, and many others, that is a DA/SA pistol using DA for the first shot.

 

[Limnophile]

At 25 feet in SA I can group about 1.5 inches 10 shots. In DA that is about 3 inches with many of those concentrated in smaller group.

Thank you for confirming my statement -- SA groups are always, on average, tighter than DA groups. Although I have never fired any of my CZs in DA, I have done a lot of dry firing at a LaserLight target. Interestingly, my results are identical to yours -- my DA groups are twice the diameter as my SA groups, which means the SA mode is 4-times more precise.

If i am shooting at someone in my house it will almost surely be at distances less then that and my DA accuracy is plenty good to hit in the vital zones.

I agree that your DA performance at the range is more than adequate for your intended purpose, but your SA performance is 4-times better. Fortunately, if you need to fire multiple shots to get the job done, your shot string will he weighted in favor of your SA performance.

However my main concern is safety and NOT discharging my pistol when I do not intend to.

I can't think of a bigger issue in firearms safety than preventing an ND.

DA long and heavy trigger pull gives me extra margin of safety in a situation where I have just awoke from deep sleep and adrenaline dump kicks in.

I agree that a long, heavy DA trigger is an effective safety mechanism. (For those who like to straw man this statement, effective does not mean perfect.)

Interestingly, DA triggers are the reason many LEOs were taught to stage their triggers to try to improve first shot accuracy. Staging a trigger when the target is a person you don't intend to shoot is, of course, a safety violation, and it led to NDs, especially when a cop manually cocked a DA revolver and when departments switched to Glocks. The penchant for trigger staging is the reason NY triggers exist.

It seems that the practice of trigger staging was not abandoned until Roger Enoka published "Involuntary Muscle Contractions and the Unintentional Discharge of a Firearm" in 2003.

No one knows for sure how their training will hold up in such situations. Those who have observed those in such situations have seen a large percentage of trained shooters with their finger on the trigger before they ever intended to shoot.

The best combat training is actual combat. Most civilians and even most cops will never see actual combat, so training is the best we can do, and the more realism and stress imparted during training the more effective it will be.

Christopher Heim, Eckhard Niebergall, and Dietmar Schmidtbleicher published "Involuntary Firearms Discharge -- Does the Finger Obey the Brain?" in 2006. Their study shows that a surprisingly high percentage of LEOs, even highly trained SWAT team members, become inadvertent and inappropriate trigger touchers under stress.

In the end do whatever you are comfortable with. For me, and many others, that is a DA/SA pistol using DA for the first shot.

I agree. I cannot make a case for Condition 2 carry being more or less safe than Condition 1 carry, only that you get better first-shot accuracy, on average, with the latter. If you can achieve DA precision that you have, that difference becomes minimally important.

 

[Llama Bob]

For any pistol I might have to fight with, condition 1 (cocked and safety on) is far preferred, along with a trigger in the 4.5-5lb range. Consistency of trigger pull, along with practice, is key to accuracy.

If that's not an option, DAO is preferable. It's going to be too heavy, but at least it'll be consistent.

And of course I would never choose to fight with a pistol if a long gun was an option.

 

[Limnophile]

^ I think the importance of accuracy is underweighted. Given that police shootings result in a hit rate somewhere between 1 out of 6 to 1 out of 3, it seems that accuracy degrades dramatically under actual combat conditions. It is for this reason I avoid overstating accuracy (when assessing probabilities, overconfidence is the kiss of death) and prefer a high capacity sidearm.

 

[Walt Sherrill]

What if the pistol doesn't land on its muzzle but on the rear of the slide and grip?

If your argument is that the likelihood of what I'm describing is next to impossible to happen, then I agree. That doesn't, however, mean that the Glock does not have more internal mechanisms to prevent an accidental discharge from a drop than a hammer fired pistol cocked but with the safety disengaged.

If the gun lands on the rear of the slide and somehow, the firing pin or striker blocking mechanism is magically deactivated -- what's going to make the firing pin or striker suddenly jump UPWARD to strike the primer? Momentum will be sending things in the other direction. If the fall causes it to hit the grip first, that could also push the slide out of battery and momentum will still be moving the critical parts away from the primer and not causing the firing pin block mechanism to be deactivated. With the Glock, you'd still have to finish compressing the striker spring before it can be released -- and I don't think that's going to happen as a result of a drop -- unless the Glock explanation of how the trigger safety works is complete BS. The extra Glock safeties you mention are nice in theory, but they may not really matter. A 110% drop-safe gun isn't really 10% safer than a 100% drop-safe gun.

With a hammer-fired gun, if you disregard the momentum that is pushing things in the wrong direction as the gun hits the ground -- we're still talking about a number of different mechanisms (including the firing pin block) that must be overcome before the hammer can fully drop and send the firing pin forward. If there's a half-cock notch (some guns, including 1911s and CZs, have them) that notch is going to prevent the hammer from striking the firing pin. If we don't disregard the momentum of the drop, the internal parts used to deactivate the FPB in most guns will also be moving in the wrong direction to 1) disengage the firing pin block or 2) to send the firing pin towards the primer! This would be true for many SA, DAO, and DA/SA guns. Even the firing pin spring itself will be a barrier for some gun!

We're back to my earlier unanswered question: can you cite an example of a real-world unintended discharge that occurred with a dropped gun that had a properly functioning firing pin block installed? Can you offer a theoretical explanation that would explain how it COULD happen with a drop. As I said earlier, maybe I'm missing something.

All this said, I wouldn't consider carrying any of my SA or DA/SA cocked and unlocked. Not because I don't think they're drop safe, but because most of my SA or DA/SA guns have relatively light triggers, and I wouldn't trust ME to do start with a holstered, unlocked gun if I were stressed and threatened. I will carry my Glock 38 with less concern, even though it doesn't have a manual safety lever, because that trigger is much less easily released than my other guns. But when things go bump in the night, I'm still wary when I grab the Glock from my bedside gunsafe. (I'd wouldn't be unhappy if my Glock had a safety like my Ruger SR9c, but I don't find myself using that safety much, either.)

.

 

[Limnophile]

If the gun lands on the rear of the slide and somehow, the firing pin or striker blocking mechanism is magically deactivated -- what's going to make the firing pin or striker suddenly jump UPWARD to strike the primer? Momentum will be sending things in the other direction.

As I recall, TR's point is that a drop resulting in the rear of the pistol striking the ground could cause the trigger to move backward enough to actuate. The trigger tab safety on a Glock prevents that from happening. However, the CA drop test protocols take such a scenario into account (per the CA DOJ):

The following six drops shall be performed:
(a) Normal firing position with barrel horizontal.
(b) Upside down with barrel horizontal.
(c) On grip with barrel vertical.
(d) On muzzle with barrel vertical.
(e) On either side with barrel horizontal.
(f) If there is an exposed hammer or striker, on the rearmost point of that device, otherwise on the rearmost point of the weapon.

The CZ 75 B and B variants pass the test, as do Glocks. I am unaware of any empirical evidence indicating one design is more or less drop safe than the other.

All this said, I wouldn't consider carrying any of my SA or DA/SA cocked and unlocked. Not because I don't think they're drop safe, but because most of my SA or DA/SA guns have relatively light triggers, and I wouldn't trust ME to do start with a holstered, unlocked gun if I were stressed and threatened.

But ... but gun safety is all about keeping your booger hook off the bang switch, Dude.

 

[Walt Sherrill]

As I recall, TR's point is that a drop resulting in the rear of the pistol striking the ground could cause the trigger to move backward enough to actuate.

I'm only vaguely familiar with 1911s, but do know that the Series 80 guns do have a firing pin block. If that gun drops onto it's muzzle, momentum, it seems to me, is going to keep the trigger forward and not send it rearward. If that same hammer-fired gun drops on the grip, I would think a lot of different things would have to be timed just right for the gun to go boom. If the gun drops on the rear of the slide or hits the hammer, and the hammer is somehow released, the hammer may not have a clear path to the firing pin. And I'm not sure it could even fall if the grip safety wasn't depressed -- as trigger movement is at least partially blocked by the grip safety! Someone more familiar with the 1911 design will have to speak up. I think timing is critical -- and all the various parts would have to work together (trigger and grip safety movement and firing pin block mechanism release) for an unintended discharge to occur. That would be an almost perfect storm of interactions that may or may not be easily achieved in a drop.

With many other hammer-fired guns, the trigger pivots, and it's rearward movement causes a trigger bar or connector to move forward. The trigger and the connecting parts all act as a single assembly and the other parts parts are much heavier than the trigger; their momentum, if the gun falls to the rear, hitting the slide or grip, is going to force them all to the rear.

A number of guns (including 1911-type guns and others with firing pin block safety mechanisms) have passed the California drop tests, and they do their tests from a lot of different drop positions. It's not clear to me that a drop (even if it causes trigger movement) will override a gun's firing pin safety mechanism.

 

[Llama Bob]

Depending on whether you are talking series 80 or 70, 1911s have several features that come into play when dropped.

First is the half-cock notch on the hammer. If a blow to the hammer somehow allows it to pass the sear, it won't get to the point of firing because the sear will engage the notch.

Second is the thumb safety. The sear cannot disengage the hammer if the thumb safety is engaged (and fitted correctly).

Third the grip safety makes it impossible to pull the trigger without depressing the safety first, so no inertial trigger pulls.

In theory a S70 could fire if dropped muzzle down due to the inertia of the firing pin, but this only happens in California drop tests, and can be prevented with any of a series 80 firing pin stop, a Schwartz safety, a light weight firing pin, or by avoiding California.

 

[Limnophile]

^ The MRI-induced AD of a 1991 (Series 80) defeated all safety mechanisms, including the FPB and the safety lock. That, however, was a very odd set of circumstances that led to that incident. As a result, all MRI patients are now led to a changing room with a locker in which to store valuables (including any firearms), and specifically told not to bring anything metal into the suite.

 

[Bart Noir]

A 110% drop-safe gun isn't really 10% safer than a 100% drop-safe gun.

Nicely said, Walt. I like your writing skills

In theory a S70 could fire if dropped muzzle down due to the inertia of the firing pin, but this only happens in California drop tests,

Bob, there is another way to get the dropped-gun discharge. If the firing pin spring is weak, and the Pre-Series 80 1911 is dropped on the muzzle, the firing pin may fly forward with enough oomph to fire the round. It is a rare thing but it has happened.

[Anecdote Warning] My friend discovered this when another guy dropped a 1911 next to my friend's foot. Both men learned just how high they could jump but nobody was hurt when the bullet fragmented into the concrete floor.

So he and I are fans of the Series 80 1911 design.

Oh yeah Bob, does the Llama part of your forum name have to do with the critters or the firearms?

Bart Noir

 

[Cosmodragoon]

A 110% drop-safe gun isn't really 10% safer than a 100% drop-safe gun.

Very good. I often find myself reminding people of how percentages actually work. (I'm also the guy who nails people for saying "quote-unquote" before the thing they mean to quote.) Here we can add a special caveat. Is anything really 100% safe? No, and the best gun safety device really is between your ears.

 

[Llama Bob]

Oh yeah Bob, does the Llama part of your forum name have to do with the critters or the firearms?

The critters. I've never actually seen one of the guns in person.

I don't have any great dislike of the S80 system (or the Schwartz safety) but I'm not concerned about a properly maintained S70 either.

 

[wild cat mccane]

You know what really stops me from jumping on the CZ SP-01?

For $30 here, $100 there, and $50 over there you end up with a good trigger: less weight, no outrageous reach, and a reset that is reasonable.

All this can be found on other pistols on the market...and I don't have to purchase aftermarket, install, and lose all the $ in resale.

Just put it in there from the factory.