Originally Posted by shawn mccarver

Although the device is marketed as a "trigger safety," as Jeff Cooper pointed out with the Glock, putting the safety on the trigger is like putting the combination on the vault door.

One purpose of the device is, most assuredly, to help to prevent inadvertent discharge.

You will, however, note that for the most part such devices are only present on STRIKER fired pistols and not on hammer fired pistols.

The reason the device is ever present on striker fired pistols is because of the possibility of inertial discharge in case of a drop on the REAR (rather than muzzle) of the pistol.

Historically, engineers figured out that semi-autos could discharge if dropped on the MUZZLE as the only thing holding back the firing pin was the firing pin spring. A heavy steel firing pin, in combination with a spring that is worn, in combination with a drop onto the muzzle from a sufficient height results in a BANG.

Colt figured this out well before WWII and one of its engineers, William L. Swartz, filed a patent application on 4-13-1937. The so-called Swartz safety was patented on 12-20-1938, patent number 2,140,946. The device was licensed to Colt's Patent Fire Arms Manufacturing Company, Hartford Connecticut. The Swartz Safety was an internal firing pin block which was deactivated when the grip safety on the 1911 was depressed.

The device was put on some pre-war 1911s (I have seen it more often on .38 Supers), but it was expensive and WWII came along, and the device was not put into war time production, nor was it added back after the war.

The weak point of its design was that it worked off the grip safety. Some thought that was its strong suit. In any event, when Colt introduced its Series 80 improvements, things were getting less business friendly from a litigation standpoint, and so a device to prevent discharge was needed in case the 1911 was dropped. Colt re-designed the Swartz Safety into the Series 80 firing pin block we know today, which differs from Swartz' patent in that the Series 80 works off the trigger as opposed to the grip safety. It is a more positive system. It was initially criticized as making a light trigger more difficult to achieve, but the only place this rumor still persists is on the internet.

The Series 80 system patent ran out and now Remington, Para, Umarex and others use it. Kimber uses the Swartz system as did S&W on its original 1911s. S&W's new system, like Springfield and many others, now use a very light titanium firing pin combined with a heavy firing pin spring to survive drop testing. Colt uses this method on its Series 70 reproduction guns and anything that does not have the actual Series 80 firing pin safety.

The main purpose of the firing pin block is to prevent inertial firing in the event of a drop on the muzzle. The firing pin block was introduced to "modern" pistols with the West German police pistol trials in the 1970s, which produced the Walther P5, the SIG P6 (commercial 225) and the HK P7 (PSP, P7, P7M8, etc.).

SIG and Walther put the firing pin block into its designs, which were, in compliance with the West German requirements, designed to have no safety lever in the traditional sense. S&W's 1st Gen Autos had the P38 style safety, which decocked the pistol and arrested the firing pin when in the ON position (down). Designed to prevent inertial discharge in the safe position, NOTHING was present to prevent inertial discharge in the event the slide mounted safety of the S&W was in the fire position (up). Because it deactivated the trigger when on, the slide mounted safety/decocker, which was difficult to take off at high speed - much more so than the ergonomically better thumb safety lock on the 1911 - Jeff Cooper gave it the nickname "Dingus," leading to the Cooper dictum, "Don't get caught with your Dingus down."

As LE doctrine changed subsequent to the West German Police trials, agencies decided that the slide mounted safeties should be carried OFF, and S&W then designed its firing pin block into 2nd Gen and subsequent designs, including all current modern duty pistols (except the 1911 E Series, which uses the light firing pin method as explained) in order to prevent inertial discharge in the event the pistol was dropped.

Enter the striker fired mechanism. Glock knew that inertia works in both directions. A striker fired pistol in which a "trigger bar" is in contact with not only the lug on the firing pin, but also the firing pin safety, and which when drawn to the rear will hit a release point causing BOTH the deactivation of the firing pin safety and the release of the striker to run forward at high speed to fire the round presented a problem not present on hammer fired pistols.

Thus, something had to be designed into the system of the striker fired pistols which would prevent inertia from causing the trigger bar to travel rearward thereby deactivating BOTH the firing pin safety and causing release of the firing pin.

Because the pistol will discharge no matter what causes the striker to move far enough rearward, the extra device to prevent inertia firing was needed.

Inertia of the kind which can cause a discharge in the 1911 is normally thought of as a drop on the muzzle, the pistol stops suddenly, and the firing pin keeps moving forward. BANG. Certain rifles, such as ARs, AKs and M1As and M14s have this same issue. Slam firing is the term applied when the bolt runs forward on such a rifle at high speed, comes to a sudden stop, the firing pin keeps moving forward and the primer is dented. Usually not enough to cause a discharge, but if you have an extra sensitive primer, well - that is when your muzzle better be pointed in a safe direction. Some AKs for the US commercial market have firing pin springs designed to prevent slam firing.

Inertia works both ways. In a striker fired pistol, the firing pin safety prevents discharge if the pistol is dropped on the muzzle. However, if a striker fired pistol is dropped on its rear end, inertia can, and will, without the little articulating trigger, cause the trigger bar to keep moving to the rear. Of course, as it does so, the firing pin safety is deactivated and eventually, if the drop to the pistol's rear is with enough force, the trigger bar moves far enough back to its release point, and BANG.

In the event of a drop on the pistol's rear, there is no finger or anything else "pulling" the trigger, so the little articulating device does not get deactivated, and the whole trigger bar is not free to go flying rearward with inertia.

Now, all sorts of people will argue that it can't happen, the force is too great for an ordinary drop, etc. Not so. Please recall the Ruger SR9 was initially introduced without the articulating trigger safety. Very quickly, it was quietly redesigned and even the Ruger now has the device.

So, that is the real purpose of the device. Do you see why it is easier to merely call it a trigger safety? It would take pages of advertising to explain the above and few would understand it or care.

I hope that information was helpful.

Originally Posted by shawn mccarver

In the event of a drop on the pistol's rear, there is no finger or anything else "pulling" the trigger, so the little articulating device does not get deactivated, and the whole trigger bar is not free to go flying rearward with inertia.
So, that is the real purpose of the device. Do you see why it is easier to merely call it a trigger safety? It would take pages of advertising to explain the above and few would understand it or care.
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Thanks for the fantastic explanation! I'm wondering about "...no finger or anything else "pulling" the trigger, so the little articulating device does not get deactivated..." The little articulating device (both M&P and Springfield designs) is also subject to momentum. Why wouldn't they also continue moving rearward and deactivate? Thanks

Originally Posted by motorcyclejoe

The little articulating device (both M&P and Springfield designs) is also subject to momentum. Why wouldn't they also continue moving rearward and deactivate? Thanks

Originally Posted by Rastoff

Ah, I assume you are the one who also posted on the youtube video. I answered there as well, but I'll post it again here.

When they do this testing they use a case with only a primer in it. This is why you see only a small flash. It would be unsafe to use a fully loaded cartridge, don't you think?

Originally Posted by rsrocket1

If you attest to the authenticity of a primer going off Rastoff, then I apologize. I trust your integrity. The "flash" just looked like it was edited into the video.

Originally Posted by Smokey74

I strongly believe in external safeties and that is why all of my handguns have a thumb safety. Sorry, guess I am "Old School".

Originally Posted by Gamecock

Savage calls it a "two stage trigger" on their rifles.

Last year, a local deputy got his keys caught up in the "safety," and his pistol went off in a school parking lot. If you depress the safety, the gun goes off. Some safety.

Originally Posted by Rastoff

Did you read the earlier posts in this thread?

Originally Posted by Rastoff

...Does anyone here actually believe that it adds to the safety of the gun?

What, if any, purpose does it serve?

Originally Posted by M29since14

To your first question, I certainly do not. To your second, I suspect the purpose served in the Glock is mainly legislative/administrative. The Glock is an import. In the S&W, I have no idea.

Originally Posted by TahoeDust

+1. Once you are used to sweeping off a safety I don't know why you would not want one.

Originally Posted by Gamecock

Didn't know I had to.

Originally Posted by Rastoff

If you had, you would have seen that it is not designed to prevent the kind of accident you referred to. As Deadeye Dick said, it's a drop safety. It will prevent the gun from firing if dropped on the rear of the slide.

Originally Posted by Gamecock

A drop safety in the middle of the trigger. BRILLIANT!

Originally Posted by Rastoff

If you had, you would have seen that it is not designed to prevent the kind of accident you referred to. As Deadeye Dick said, it's a drop safety. It will prevent the gun from firing if dropped on the rear of the slide.

Originally Posted by Muss Muggins

The trigger safety on a Glock is not a drop safety. A plastic trigger attempting to overcome three metal springs will in no way generate enough inertia to complete the firing cycle if if the pistol is dropped on the back of the slide from Mars . . . Glock's drop safety is an entirely different mechanism.

Originally Posted by Muss Muggins

The trigger safety on a Glock is not a drop safety. A plastic trigger attempting to overcome three metal springs will in no way generate enough inertia to complete the firing cycle if if the pistol is dropped on the back of the slide from Mars . . . Glock's drop safety is an entirely different mechanism.

Originally Posted by Muss Muggins

But did the Glocks offered to the Austrian military also have the trigger safety?

Originally Posted by Rastoff

It is a drop safety, just not the one they talk about a lot.

It's interesting that all these questions and doubts were answered three years ago when I started this thread. All the answers are there if you'll just go to page one. In fact, the best explanation is in post #3.

Then, in post #48, I put up a video showing how a plastic trigger can indeed develop enough inertia to overcome the springs etc. in the gun to cause it to fire.

You do realize that the force generated, when dropping something like a pistol onto a hard surface, is in the thousands of Gs, right?

Originally Posted by scattershot

To me, a safety is a device that prevents the weapon from firing if the trigger is pulled inadvertently. I know, I know, keep your finger off of the trigger. Well, other things can pull a trigger besides a finger, and that's why I like a thumb safety, even on an M&P.

Originally Posted by Rastoff

It is a drop safety, just not the one they talk about a lot.

It's interesting that all these questions and doubts were answered three years ago when I started this thread. All the answers are there if you'll just go to page one. In fact, the best explanation is in post #3.

Then, in post #48, I put up a video showing how a plastic trigger can indeed develop enough inertia to overcome the springs etc. in the gun to cause it to fire.

You do realize that the force generated, when dropping something like a pistol onto a hard surface, is in the thousands of Gs, right?

Originally Posted by Deadeye Dick

I find it somewhat amusing that many of the same folks who would have no qualms about carrying a Snubby DA revolver in a jacked or pants pocket (often times even without a holster) get all tweaky about a striker fired pistol sans thumb safety.

Originally Posted by Deadeye Dick

I find it somewhat amusing that many of the same folks who would have no qualms about carrying a Snubby DA revolver in a jacked or pants pocket (often times even without a holster) get all tweaky about a striker fired pistol sans thumb safety.

Originally Posted by Hapworth

As somewhat amusing as I find equating two entirely different actions, with entirely different trigger characteristics and pull weights?

Originally Posted by Muss Muggins

Depends on whether or not you have the NY trigger installed in your Glock . . . (as for the actions, if you pull the trigger to the rear, either configuration will fire, I think.) Y'all acting like the pistol will go off in your pants is similar to the blood in the streets CCW/Open Carry arguments. Ain't gonna happen. Learn how your gun works, and exercise a little caution.