The recent controversy regarding the drop safety characteristics of SIG’s P320 handgun has some taking a closer look at their handguns. Drop safety is something that – in theory – is so mature in modern handguns that it should be a non-issue, but with so many different variations on the same theme (that theme being “Glock”) in the market today, how do we know these guns are really as safe as they could be? With that in mind, it’s worth taking a closer look at what makes a modern striker-fired handgun drop safe, and that’s just what Tom Jones of Pistol-Training.com has given us in a recent forum post. Jones lays out what makes a Glock a “Glock”, in other words, the carefully designed safety features of the company’s handguns which make them as difficult to accidentally discharge as possible:

Using generic terminology, the important features of a mechanically “drop safe” striker design, IMO, are:

1. A supported/blocked sear that can NOT release the striker unless the trigger is moved.

With Glocks, the “sear” is the the trigger bar. The trigger bar is supported by the so-called drop-safety “shelf” of the trigger housing. The trigger bar can not be displaced downward (and release the striker) unless the trigger is moved sufficiently rearward to clear the “shelf”. Designs like the VP9, P320, and PPQ don’t have this. I don’t have a PPQ, but both the P320 and VP could have this with slightly different trigger bar designs. However, this feature requires:

2. A properly designed and functional trigger “safety”. It’s important to understand that trigger “safeties” are not, and should not be thought of as, traditional safeties — because they aren’t. The purpose they serve is to prevent inertial movement of the trigger — that’s it. When I say that the trigger safety needs to be properly designed, I mean that it needs to intercept/interrupt trigger motion before any of the normal actions of trigger motion happen, i.e., that movement can’t result in the sear being unblocked/unsupported or the firing pin block being disengaged. Another aspect of “properly designed” is that the distribution of the mass above/below the trigger safety pivot point are such that any inertial event that would cause the trigger to move, would also cause the trigger safety to remain engaged.

While it’s not exactly fair to use as an example since it is a prototype and was never actually released, the SIG P320 prototype tabbed trigger safety is an example of one that’s not properly designed. Without depressing the trigger safety, the the trigger moves sufficiently rearward to fully disengage the firing pin block. No es bueno.

3. A firing pin block — preferably one that is directly acted on by the trigger bar and not another intermediate part (due to the attendant complications with regard to inertial events).

This is, in my opinion, the last line of defense and should only prevent a discharge if there were significant part(s) failures elsewhere in the gun.

Now, a supported sear that requires trigger motion before the striker can be released, typically means that you now have to operate the trigger to disassemble the pistol — and there have been a LOT of unintentional discharges because of this. The way that SIG and HK designed the takedown of the P320 and VP9 are great. They have a take down lever that can only be rotated if the slide is to the rear and the magazine has been removed. If the redesigned trigger bars I mentioned above were added to these guns, this would no longer be the case and the triggers would need to be operated (with the slide locked to the rear as the takedown lever is rotated).

Does a supported sear design require you to operate the trigger for disassembly? No. It’s possible to design a gun such that it has a supported sear and a VP9/P320 trigger-less takedown method. There are a number of different ways to accomplish this. One way is instead of having the sear be displaced by the action of the takedown lever, you have the entire sear housing (or trigger housing for a Glock) lowered a few hundredths of an inch when the takedown lover is rotated. Another is having a mechanism in the slide itself such that you can rotate the striker assembly so that it doesn’t re-engage the sear when the slide goes forward. There are many more. Before anyone tells me how either of these ideas won’t work or point out a “fatal flaw” in the idea, please don’t. I’m not presenting every possible detail of the designs here, just enough to get my point across — there is a lot more detail, I just lack the time and desire to fully describe it now. 

Coincidentally, it is possible to do the same thing with a Glock — disassemble it without operating the trigger with the slide forward — you just have to prevent the trigger bar from popping up as the connector is displaced inboard when the slide returns forward. It’s easier to do on an unmodified Gen5 because of the right side slide stop lever. 

I could write/talk a lot more about this sort of thing, but my typing skills are terrible and I’m out of free time.

Also, as an aside, I should point out that despite the trademarks filings, the thing that makes a Glock a Glock is not the external shape/appearance — it’s the internal parts and design. I say this to only point out that if someone puts aftermarket components (especially firing mechanism related components) into a Glock, it’s not really a Glock anymore. There are plenty of aftermarket trigger components available that alter/reduce things to the point that the internal “safeties” no longer truly exist or exist in name only.

As usual, I’m just some guy on the internet with an opinion. Many, if not most, people will disagree with me. I’m OK with that. 

Jones’ description of the safety features of Glock handguns is so complete and easy to understand that I don’t think I need to add much text of my own. So instead, I recorded a short companion video showing these features in real time:

Factor Glock handguns are some of the safest weapons around, but they are not (contrary to the company’s slogan) perfect. Disassembling a Glock requires pulling the trigger, which when combined with carelessness, can result in a negligent discharge. Other companies have sought to improve upon the Glock’s design with mechanisms that allow disassembly without pulling the trigger, but this often results in the introduction of a failure point which Glock’s do not have. Put simply: In order to disassemble a striker-fired handgun, the sear has to be able to move without pulling the trigger – and if that is possible, then (unless the mechanism has been extremely carefully designed) the sear can potentially release the striker and fire the weapon without the trigger’s involvement!

H/T, Tamara Keel