This is another SIG Mechanics video that details how adjusting a trigger to reduce pretravel (takeup) can affect the pistol’s internal safety mechanism that blocks the striker until the trigger is pulled.

Even if you don’t have an adjustable trigger, the video provides an excellent visual demonstration of how the striker safety lever and safety lock mechanism works.

https://www.youtube.com/watch?v=8WqpL7A5zd8

So if I read your synopsis on the other thread correctly is that what happened to that officer in the "bend over" thread?

It would be something to ask about in an investigation, but I have no information that that officer had an adjustable trigger in his pistol.

Unfortunately, whenever something like that happens, the initial incident and all the claims and speculation get splashed all over the Internet. Any follow-up information, not so much.
My personal belief is that somehow something got on the trigger, pulled/pushed it to the rear, and the pistol functioned normally just as it was designed. Nothing else seems the least bit possible to me.

In line with all that and to reiterate what I mentioned in the other thread, the sear of upgraded P320 pistols has two intercept points, the second of which should stop the striker if it somehow became dislodged from the first (primary) point without the trigger's being pulled.

But although the video does not make the claim, I strongly suspect that overadjusting an adjustable trigger not only affects the engagement of the safety lock with the striker, but also the engagement of the striker lug with the sear. If true, then the second sear intercept point would probably be rendered ineffective as well. But my speculation only.

SIG's own initial read on that incident was that the officer was using a Safariland holster that was NOT designed for his particular P320 configuration (pistol with NO weapon light). Without the WML in place on the pistol, it (apparently) allows the weapon to shift and move inside the holster. Through my own experiences with other holsters designed and made to accommodate a Surefire X300 on a G19-sized Glock and holstering my G23 without a WML onboard, I can certainly believe that a P320 could shift around in such a similar Safariland holster. The main difference between the SIG and the Glock of course is the lack of a "trigger safety" built into the trigger shoe. If the gun shifts around enough that any part of the shoe comes into contact with an internal surface of the Safariland holster and then the movement of the gun is enough to cause the trigger to pull...

This at least in part could also explain why law enforcement is having this problem while the civilian world generally isn't, since holsters are typically issued by the department and not generally purchased and acquired by the officer through other means. Private citizens tend to buy a holster that's EXACTLY configured for how our guns are set up rather than settle for a holster that is a compromise configuration. Of course if a civilian has such a similar unintended discharge, they're also less likely to fess up about it as well. Certainly they're not going to do it on the internet, just to incur the wrath of indignant 'gun safety experts' who will shame such a person for using the "incorrect" holster and the attention of LE for the discharging of a firearm, unintended or not.

quote:

Originally posted by monoblok:
pistol with NO weapon light

Thanks for that update, and certainly a possibility to be aware of.
When training I use a dummy weapon light to keep my real lights clean and when using holsters designed for WMLs because of the poor weapon fit without them.

Added: This is more applicable to the other thread, but because it’s been mentioned (and it’s my thread ), I’ll say a bit more about an ill-fitting holster.

I tried a P320 in a Safariland hard “tactical” holster designed for a WML, but with no light attached. With the pistol properly locked in place, the gun moved very little. But without the light it’s possible to rotate the pistol so that it fits into the holster, but the trigger guard prevents the gun from going down into its proper locked position. With the gun up like that the trigger guard is completely open for a drawstring or piece of garment fabric to get in and contact the trigger. If the gun is then bumped so that it then drops down into the holster, the trigger could be pulled, causing a discharge.

Again, speculation only, but if an officer had drawn his pistol at the start of a confrontation but then holstered it before going hands-on with an arrestee, he might not notice that it wasn’t holstered properly. And then something would have to get into the trigger guard, and then …, yes, I know. But very many bad things result from a sequence of unlikely events.

Added part deux:
The improperly holstered pistol as described above. The pistol cannot be placed in that position with a WML attached.

It shouldn't happen, but I can totally see an agency issuing a WML holster to a guy without a WML and telling him to make it work. Or maybe he took it off on his own. Either way, bad ju-ju.

I'm not sure I'd say that "civilians" are all that much better, though. I imagine most who are involved enough to post here spring for quality stuff, but I've seen some guns (including striker-fired guns) being carried in some truly awful floppy nylon universal garbage. Sadly, that's usually what's available off the shelf at the LGS, too, because most owners don't want to/can't afford to carry the overhead of a wide variety of quality gun-specific holsters. Then your stereotypical new gun buyer comes in and wants to get a holster with his new gun, and walks out with something that's entirely likely to help him blow a hole in his leg.

I don't shoot my 320's much anymore but I bought the Grayguns flat trigger for my 365. It is adjustable to limit OVERtravel. Do you think this trigger compromises the safety factor as well?

quote:

Originally posted by pedropcola:
I don't shoot my 320's much anymore but I bought the Grayguns flat trigger for my 365. It is adjustable to limit OVERtravel. Do you think this trigger compromises the safety factor as well?

It should not (and he does mention that at one point in the video). What is happening with the pre-travel adjustment is that it can be adjusted so far that it's basically pulling the trigger...the set screw is holding it far enough to the rear that it's engaging the safety lever and defeating the firing pin block. An over travel screw does not do anything but bottom out against the frame of the FCU after the trigger is pulled, so the only way you could really go wrong with it is to adjust it so far that you can't pull the trigger far enough to drop the sear.

This is not a problem with the design of the P320...it could theoretically happen on any gun with an adjustable trigger that uses a similar safety lever/firing pin block assembly. If you install an aftermarket part and then adjust it to the point that you've defeated a factory safety device and taken every last micron of pre-travel out of the pull, you can't blame the design of the gun when it NDs (I know that's not what Sigfreund is suggesting...I'm just making the point).

I figured it was ok since it never mentions anything but overtravel but I wanted to hear some other opinions. Thanks.

There are specific reasons Bruce did not include a pre-travel adjustment screw with his P365 and P320 triggers.

I think this video does an excellent job of explaining why pre-travel adjustment was not included.

The descriptions for the P320 and P365 triggers on the Grayguns website include the statement that they "preserve factory sear engagement and all mechanical safety values."

The Armory Craft trigger with both pre and over adjustment screws has very specific installation instructions. First caution is that the trigger is only for competition pistols.

The pre adjustment is to achieve a 2mm free travel before the wall is felt.

The over adjustment is to ensure sufficient travel that the striker is released.

What is noteworthy, of course, is that both adjustments rely on Loctite 242 to maintain screw position. I can see this as useful and beneficial for optics. But, for a freely traveling screw, without any torque to apply, adding a huge amount of friction to the threads, relying on thread locker alone seems risky for a duty weapon.

I am not a good shooter, compared to Max Michel, or even Parabellum. But, I cannot at this time see how a better trigger is necessary [bold] for me [/bold] at the competitions and training. My shortcomings are so very basic compared to trigger action.

So, for now, I won't be installing the competition trigger on my duty pistol. I may try it on my competition pistol. But, as competition is where the highest risk of discharge exists, I think I'll have a pre-event check on that 2mm gap before the wall.