Glock's drop safety.

[nikon777]

Originally Posted by English
After far too long a time it has dawned on me that the mistake in this thread has been to consider the "trigger" safety in isolation. We should have considered the safeties of the Glock as a system.

First, the Glock is intended to fire if you pull the trigger with a round in the chamber. The weight and length of trigger pull adds a small margin of safety against a "twitch" of the trigger finger but not much in comparison to a cocked and unlocked 1911. It has no where near the margin of a revolver in double action mode. If your finger is on the trigger when you are startled enough you are very likely to pull the trigger hard enough to fire the piece. To this extent, as many keep saying, the primary safety is between your ears. Handle the gun sensibly and you won't have a negligent discharge.

Second, with the negligible exception of protecting against a push or pull against the side front of the trigger, all proper Glock safeties guard against drops, but not always as you might think.

A drop of a solid object onto a solid surface can produce remarkably high G forces. A drop where the pistol lands on the top of its slide could easily unsafe the firing pin safety as its inertia would easily overcome the spring loading. Fortunately the same G forces would push the trigger bar upwards, relative to the normal orientation of the pistol, and push it more firmly into engagement with the firing pin. So that is a safe drop orientation.

The most serious risk is from a drop onto the tail of the slide. Here the full mass of the trigger and trigger bar will be pushed back. If the impact is large enough then, without the trigger safety, this force could, in principle, push the trigger bar back far enough to act as though the trigger had been pulled. That is, it would disengage the firing pin safety, further cock the firing pin against its spring, cam the trigger bar down against the connector/disconnector and fire the pistol. The trigger safety stops this from happening because it is in neutral balance against this force and its spring holds it in place unless the pistol is spinning very rapidly, as in the infamous Frisbee test.

Lastly we have the simply named drop safety. This provides a guide for the cruciform of the trigger bar which prevents it moving downwards until the trigger is pulled most of the way back. Ostensibly this guards against an upward impact on the but of the pistol forcing the trigger bar down and releasing the partly cocked firing pin. What would happen if it did? The gun would not fire because the firing pin would be blocked by the firing pin safety which would be held more strongly in its safe position by this direction of impact.

So what is the drop safety for? It protects you from the circumstance where you drop your Glock, perhaps in the course of a fight, then pick it up and try to shoot. Without the drop safety the result might not even be a click because the firing pin would have been disengaged from the trigger bar cruciform by the drop. That is, the firing pin would be fully forward against the firing pin safety. If it is not partially cocked it will not fire! So the drop safety protects you from the gun not firing when you need it to fire rather than from firing when it shouldn't fire.

It should be clear from this that the PRIMARY mechanical safety of the Glock against accidental discharge when the gun is dropped is the trigger safety.

There is no safety against it being fired once it is in your hand with your finger on the trigger and nor should there be.

There is no safety worthy of the name against discharge when something other than your trigger finger snags the trigger and pulls it back. This is actually a major failing of what is an ingenious piece of engineering.

All mechanical systems can fail and in this case we are trusting a lot to a small engagement of two pieces of cheap molded plastic. Apart from that the firing pin safety can get stuck in the up position if it gets too dirty, the firing pin/cruciform engagement can be insecure if it has been modified and/or damaged so that there is a very small engagement but this combination would also probably need a soft primer to fire.

For what it is worth, I do not believe that any pistol design solves the re:holstering/snagging problem in a reasonably fail safe manor. A manual or thumb safety will do so provided you remember to put it on safe every time you holster. The psychological fact is that the time you are least likely to do this is in the immediate aftermath of combat. This is also the time when you are most likely to be clumsy as you re-holster.

English

[Lazarus]

Nikon where's the cliff-notes and what's the purpose of this post? That said I'd noticed my XD is way safer than my Glock. I can't tell if its loaded and theres no front serrations for me to press check it. The XD has the indicator at the top, the side and the cocked indicator as well as the serrations at the front.

[nikon777]

Originally Posted by Lazarus

Nikon where's the cliff-notes and what's the purpose of this post? That said I'd noticed my XD is way safer than my Glock. I can't tell if its loaded and theres no front serrations for me to press check it. The XD has the indicator at the top, the side and the cocked indicator as well as the serrations at the front.

The post shows that a Glock can fire if dropped given the correct circumstances. Check your FP safety when cleaning is a good idea. Ill be doing this on my 19 from now on. Its in relation to a thread on GT about a older G19 going off when dropped.

Your G26 has a LCI on the side. If you can feel the notch on the extractor, its loaded, if its flush, its not.

[agalindo]

Originally Posted by nikon777

The post shows that a Glock can fire if dropped given the correct circumstances.

Same thing can be said about the XD. The striker safety on the XD works on the same principal. A metal tab using spring pressure to block the striker located on the slide.

[edit]

I was just thinking about this last night.

[headhunter]

The extractors on my Glock pistols stick out when the chamber is loaded, allowing visual and tactile confirmation of loading. I've heard the argument that the XD's loaded chamber indicator is better...I'm not sold on the idea; I still ALWAYS press check. I'm not a big fan of press checking with the support hand forward of the ejection port. I think it is too easy to allow your hand to cross in front of the muzzle. So forward serrations are not a big deal to me.

I love both the XD and GLOCK weapon platform. If you follow the basic rules, you should never have a problem with either.

[nikon777]

Originally Posted by agalindo

Same thing can be said about the XD. The striker safety on the XD works on the same principal. A metal tab using spring pressure to block the striker located on the slide.

[edit]

I was just thinking about this last night.

Yes sir.

[Lazarus]

Originally Posted by nikon777

Your G26 has a LCI on the side. If you can feel the notch on the extractor, its loaded, if its flush, its not.

I never noticed this. I will check it out when I get home.

[Jcobb]

In order for a Glock to fire, the trigger safety has to be disengaged, which allows the trigger to move rearward, moving the trigger bar rearward. This allows the firing pin safety to be disengaged. Further rearward movement disengages the drop safety, thereby allowing the firing pin the travel forward. If there is a trigger safety failure and there is enough force to move the trigger bar rearward, I guess it could happen. IMHO it is very unlikely to happen though.

[nikon777]

I'm still pretty confident that tossing my 19 across the floor wouldn't discharge it. Then again the Glock did fail the DEA test if I recall correctly. Some one refresh my memory. Either way, as mentioned I'm quite confident in my 19. I will however be checking the FP plunger for function after cleaning etc.

[G60]

no, no, that can't happen. see glocks are perfect, says so in the literature.

http://www.thegunzone.com/glock/upgr...q.html#frisbee

"In the DEA tests the slide came off the frame and the pistol discharged."