Posted: 7/29/2025 6:48:57 PM EDT
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I know, another thread on this topic, but I think I have a workable theory. I’d like to be told why I’m wrong and my idea is impossible. We know from the “punch test” the P320 striker block safety is unreliable. Punch Test We know from the “one millimeter test” that the secondary sear doesn’t necessarily catch the striker if the sear has pivoted, even if only enough out of the way that slide/frame clearance can allow it to fire. Slide Movement Test This video shows how the sear is built, and I will borrow an image from it. Striker Function and image attribution We want to explain how a SIG P320 must fire (1) in a holster with no trigger manipulation, (2) through normal use of the handgun, (3) in a way that is not repeatable after the fact, and (4) would specifically affect the P320 and not other common handguns. I theorize that a pistol in a holster carried in a typical muzzle-down orientation allows for ingress of debris through the back of the slide/frame. This piece of debris could be anything which exists in the environment and can fit in that gap. It then fits into what I will refer to as the “V trap” between the back of the sear and the striker tail, illustrated below with an arrow. Attached File We know this area is accessible from the back of the slide because of the punch test, and that this sear can be moved down without a trigger pull due to that same test. We know that the striker block safety doesn’t necessarily successfully block the striker in all instances. We know that a pivoted sear, as it has pivoted in the millimeter test, will not reliably catch the striker on the secondary sear. It also shows us, as expected, that slide/frame clearance and the movement inherent to that does affect sear engagement, allowing these two components to move apart and back together. If a piece of debris of the appropriate size falls into the “V trap” while the pistol is being carried normally it can wedge in that V. Then, every time the slide is pushed against the frame by normal movement of a pistol in a holster that piece of debris pushes the sear farther down and when the slide moves back away from the frame (because of the magazine spring) this contaminant falls under gravity and wedges itself a little bit farther in until it pushes the sear down too far and the striker releases because the sear has pivoted. The secondary sear is also moved out of the way because the sear did rotate, and the striker block safety is unreliable and may have had sympathetic movement with the sear. It is not repeatable because as soon as the striker releases this small bit of contaminant is free to fall wherever it may and be as unnoticeable as any other fleck of dirt. In clean conditions you can’t make the striker slip because there isn’t a piece of debris. Why doesn’t it affect Glock? The Glock sear and striker engagement has no V configuration at the rear for the foreign contaminant to become trapped in and can’t be moved out of the way of the striker without substantial trigger pull because of the trigger housing blocking it. Why doesn’t it affect S&W with their M&P? The S&W sear doesn’t have that shelf at the rear for its sear spring like the P320 does. It doesn’t affect anything hammer fired because the sear and hammer are both in the frame so have no play between them during slide/frame movement during normal carrying. I’m not familiar with every design of striker fired pistol. In conclusion… The P320 can have the sear/striker engagement wedged apart by a small foreign contaminant due to the geometry at the rear of that engagement. The P320 sear has nothing to prevent it from pivoting independent of the trigger, even on manual safety equipped models. The P320 when afflicted by this contaminant eventually reaches a state in which slight bumping of the pistol will fire it. The striker releasing frees this contaminant, leaving no lasting evidence on the pistol and no repeatability in controlled lab conditions. Other pistol designs I am familiar with do not afford this opportunity for a foreign contaminant to wedge in and/or have more reliable striker block safeties. Hammer fired pistols are immune due to sear engagement not being affected by slide/frame clearance. Depending on the exact size of the foreign contaminant and the amount of movement the pistol experiences this could happen almost immediately or very slowly over the course of days, weeks, or months. It would almost exclusively happen to pistol in a muzzle-down orientation when being bumped, but could happen to a pistol in another orientation if it is already at the point sear engagement < slide/frame clearance. I put a lot of thought into this, but I’m not an expert on the P320 and also am not intimately familiar with the design of every handgun which is routinely carried. I humbly submit my theory to be picked apart and proven wrong by people more knowledgeable than me. Thank you for your time if you bothered to read this and gave it consideration. |
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Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. |
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Quoted: Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. |
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Quoted: While I have been convinced that there is a real issue with the P320. That SIG should have addressed years ago. It seems odd that NO ONE has positively identified the issue. Yet so many blast all things SIG USA. One of my favorite handguns is the SIG P210A. I actually have videos on it that I make a small pittance of money from people watching. I bought it in 2022. I have no axe to grind with SIG, and I like their product that I own. I do think the P320 has something going on and this situation could have been handled much better and more transparently. All that said, this is a common handgun and if it has a safety flaw it needs to be known. I’m just trying to help identify a potential issue and have nothing to gain either way. |
| Alternate theory is that the slide to frame fit has enough clearance on some guns for the sear to “walk” and release the striker over time. Every time the gun is racked the position and relationship of the sear and striker change in such an instance making testing a roll of the dice as to if the behavior is observed. |
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Quoted: I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. |
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Quoted: Alternate theory is that the slide to frame fit has enough clearance on some guns for the sear to “walk” and release the striker over time. Every time the gun is racked the position and relationship of the sear and striker change in such an instance making testing a roll of the dice as to if the behavior is observed. All pistols have slide to frame clearance to some degree, some more than others. So that alone can’t be the cause, only a part of the cause. If all other pistols also have slide to frame clearance, what is different about the P320 specifically that allows this to happen? We have to articulate why the sear is different to allow this walking to take place. My theory essentially is sear walk as you describe, I’m just postulating how it can happen on a P320 but not similar pistols. |
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I just received a long email from Sig explaining the bad press and defending the 320 and all the rigorous FBI and military testing and overly safe function built into it... I just skimmed it, it was pretty damn long. I've never received a message quite like that... I don't own one but have ordered ammo from Sig and am on their mailing list so I suppose everyone got the same thing.. Kinda sad, I don't have a problem with Sig although they've become a hyper marketing and lifestyle sales company in the last couplea years... but pretty sad nonetheless |
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Quoted: I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. Quoted: Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. |
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Quoted: Wouldn't it be a bitch if the drop safety upgrade is what caused all this? Just a real bitch. I have an original P320 that I never sent in for the upgrade. I tried the 1mm test and had to get the trigger to the absolute edge of the break point and then pinch the slide to get it to go off(empty of course.) I honestly think the movement made me pull it the rest off the way. This really is a more recent phenomenon so I wouldn't be surprised if the problem has something to do with the new triggers. My $.02 |
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Quoted: You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. Quoted: Quoted: Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. Really, though, why can’t it be a thumb nail clipping of a specific size? A perfectly round bead, for example, might not have enough “bite” to reliably be retained whereas a small piece of sand, nail clipping, etc. does. and it’s unlikely anyone encounters a round bead. If I can discharge a P320 by dropping a thumbnail clipping in the back of it and moving the slide, then at that point I’ve shown one possibility… that a certain thumbnail clipping in the back of the slide followed by normal carrying manipulation can cause it to fire. Which means there would be a repeatable method of defeating the safeties of a P320 by clipping your fingernails in a squad car. |
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At this point, all that's left to solve is the sear slippage since we know the striker safety doesn't work (among a million other things) in some guns. With that in mind, I think your theory is a good one and ranks at the top. The only other theory I think holds equal merit is that the sloppy frame/slide fit (which I would argue is significantly sloppier than other major striker guns) combined with shitty machining (like the burrs seen on the MSP guns) allows the striker/sear to walk off of each other with movement and not fully reset. I don't think these are mutually exclusive, for the record. Both could definitely be true. |
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Quoted: Really, though, why can’t it be a thumb nail clipping of a specific size? A perfectly round bead, for example, might not have enough “bite” to reliably be retained whereas a small piece of sand, nail clipping, etc. does. and it’s unlikely anyone encounters a round bead. If I can discharge a P320 by dropping a thumbnail clipping in the back of it and moving the slide, then at that point I’ve shown one possibility… that a certain thumbnail clipping in the back of the slide following by normal carrying manipulation can cause it to fire. Which means there would be a repeatable method of defeating the safeties of a P320 by clipping your fingernails in a squad car. Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. Really, though, why can’t it be a thumb nail clipping of a specific size? A perfectly round bead, for example, might not have enough “bite” to reliably be retained whereas a small piece of sand, nail clipping, etc. does. and it’s unlikely anyone encounters a round bead. If I can discharge a P320 by dropping a thumbnail clipping in the back of it and moving the slide, then at that point I’ve shown one possibility… that a certain thumbnail clipping in the back of the slide following by normal carrying manipulation can cause it to fire. Which means there would be a repeatable method of defeating the safeties of a P320 by clipping your fingernails in a squad car. Thats not how the scientific method works, but you're free to give it a try. |
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Quoted: At this point, all that's left to solve is the sear slippage since we know the striker safety doesn't work (among a million other things) in some guns. With that in mind, I think your theory is a good one and ranks at the top. The only other theory I think holds equal merit is that the sloppy frame/slide fit (which I would argue is significantly sloppier than other major striker guns) combined with shitty machining (like the burrs seen on the MSP guns) allows the striker/sear to walk off of each other with movement and not fully reset. I don't think these are mutually exclusive, for the record. Both could definitely be true. I do not disagree at all. Sloppy fit means more movement with each “bump cycle”, so increases the speed at which this can happen. Poorly finished surfaces can cause just enough extra “lag” in the sear popping back to where it should be that it allows the contaminant extra time to move. During normal use this exists already. The slide and in turn the striker is being pushed “up” by the cartridge stack in the magazine acting on the slide. The sear is only being pushed that same direction (pivoting, so partially perpendicular at some vector) by the comparatively weaker sear spring. Slide moves faster than sear, enhancing the gap just long enough for the contaminant to move down into that V a slight bit more. |
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Quoted: Thats not how the scientific method works, but you're free to give it a try. Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. Really, though, why can’t it be a thumb nail clipping of a specific size? A perfectly round bead, for example, might not have enough “bite” to reliably be retained whereas a small piece of sand, nail clipping, etc. does. and it’s unlikely anyone encounters a round bead. If I can discharge a P320 by dropping a thumbnail clipping in the back of it and moving the slide, then at that point I’ve shown one possibility… that a certain thumbnail clipping in the back of the slide following by normal carrying manipulation can cause it to fire. Which means there would be a repeatable method of defeating the safeties of a P320 by clipping your fingernails in a squad car. Thats not how the scientific method works, but you're free to give it a try. What else besides a fingernail clipping would you use to scientifically prove a fingernail clipping can fire a pistol? And if a fingernail clipping can do it, then it can fire without a trigger pull. |
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Something is reducing the sear contact, that seems obvious. The holsters that this keep going off in all index to the gun by the ejection port, I think that is a factor as well. The movement of slide to frame seems to affect the sear engagement, so if the holster is holding the slide firmly, but normal body movement is pushing the grip around, it seems logical that it could be causing the sear to creep off the striker. Add in debris and things get fun. |
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Quoted: What else besides a fingernail clipping would you use to scientifically prove a fingernail clipping can fire a pistol? And if a fingernail clipping can do it, then it can fire without a trigger pull. Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: Its as good a theory as any at this point. Is there a different theory you believe to have equal merit that also satisfies the necessary conditions? I can definitely be persuaded. I also think the P320 is firing for various reasons, some of them very conventional ND or AD reasons. It’s possible there could be more than one unconventional reason. I didn't post it to be dismissive, because I don't think its a bad theory, but we simply don't have a scientific method to test it. So it just stays a theory, just like all the other theories up to this point. I didn’t take it as being dismissive. I was just wondering what the other theories are. I wonder if there is a way to scientifically test this. Introduce a correctly sized piece of contamination and then just work the slide/frame apart and back together a few hundred times. You need to get a control example and then several examples and start introducing contaminants in a uniform, repeatable method. You'll need uniform, standardized analogues for the contaminants, it can't be a fingernail clipping you just got from your thumbnail. Until you do all thay, its just wondering out loud. Really, though, why can’t it be a thumb nail clipping of a specific size? A perfectly round bead, for example, might not have enough “bite” to reliably be retained whereas a small piece of sand, nail clipping, etc. does. and it’s unlikely anyone encounters a round bead. If I can discharge a P320 by dropping a thumbnail clipping in the back of it and moving the slide, then at that point I’ve shown one possibility… that a certain thumbnail clipping in the back of the slide following by normal carrying manipulation can cause it to fire. Which means there would be a repeatable method of defeating the safeties of a P320 by clipping your fingernails in a squad car. Thats not how the scientific method works, but you're free to give it a try. What else besides a fingernail clipping would you use to scientifically prove a fingernail clipping can fire a pistol? And if a fingernail clipping can do it, then it can fire without a trigger pull. Nothing, I guess. You should move on to the testing stage then. |
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Quoted: The mechanism seems plausible but I dont see how a fingernail has enough mass to wedge them apart even over time. Now maybe a fingernail fall in yhere and during firing gets sandwiched between sear and striker? All it has to do is land there in that V and just be perched, as soon as you bump the slide you get a bit of movement and it falls into the V a smidge more and is wedged and held by the sear and its spring. (Edit: At this point turning the pistol in any orientation will not free it, because it is pinched. It is held. Only cycling the action or firing will free it.) It’s not a matter of mass. All objects fall at the same rate regardless of mass “in a vacuum”, but in this small of a scale the air resistance of a falling fingernail clipping is negligible. I use a fingernail clipping as kind of a joke of how inconsequential this contaminant could be. It just needs to be something small enough to enter the V, and big enough to overcome whatever the sear engagement dimension is. It could potentially even wedge the gap open and a second larger piece of contaminant could enter later and take its place. Sand, corn dog crumbs, coarse ground black pepper or salt, boogers, that sleepy sand in your eyes… you name it. Random environmental debris. |
| Seems like opposing angles would add a bit of safety margin to that V. The M2 Browning sear to cocking pice angle is a 90°. But that is for a machine gun. Barrett made the angle 4° offset from that. Also made the cocking piece the same 4° offset so that the reciprocating action would make it a little more difficult to upset the sear. Made for a slightly heavier trigger pull though. Seems the 320 would benefit from slightly increasing that angle. |
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Quoted: I wonder what a comparison between shake awake events and holster time prior to the event would show? Probably not a whole lot, honestly. Lots of variables. The three big ones are the parameters of the contaminant, the specific amount of slide/frame clearance, and the number of times you bump the slide. Leave it in a holster in a safe for years, nothing happens. Carry it around in a clean lab room for years, nothing happens. Try to test this with the barrel aimed horizontally, nothing happens. It has to be carried in the real world in a muzzle down orientation most of the time, although once the V pinches an object just turning the pistol on its side doesn’t reset the clock. Cycling the action does. That said, a perfectly sized bit of contamination at the exactly right moment could theoretically probably make the pistol… slam fire? Almost act as an improvised autosear. That would be extremely unlikely. Regardless, it could happen almost instantly with a piece of debris just the exactly right size. All that said, the more time a pistol is carried in a holster without manipulation means more chances for the right piece of debris, followed by enough bump cycles to allow it to move the sear. More time carried in the environment increases likelihood, but doesn’t guarantee it will happen and also doesn’t mean a pistol chambered very recently is immune entirely. |
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The only sticking point I can really see (and this doesn’t mean your theory isn’t accurate) are the military discharges, to include the one with Airman Lovan last week. By necessity, I’d assume this failure mode would require a gun riding around in a holster without being manipulated (unloaded, slide racked, fired, etc) for some decently large chunk of time. I’d imagine a few days at minimum, likely longer. This is certainly plausible with civilian LE. On the military side of the house, it’s basically an impossibility, though. I guarantee you Airman Lovan had loaded that gun mere hours before the shooting (or even less, depending upon how early this happened in his shift). Hardly enough time for this failure mode to occur. I won’t outright say that makes your theory a complete impossibility, but it makes it a lot less likely, IMO. That out of the way, we’ve seen no official report of the FE Warren shooting incident, so it’s hard to say with certainty exactly what happened. Many of the other military reports are heavily redacted and don’t include video footage, so once again, it leaves some questions unanswered. Your theory is certainly plausible and accounts for all of the variables, though. I’d be interested to see if someone could cook up a repeatable testing protocol to look into it more. |
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Quoted: The only sticking point I can really see (and this doesn’t mean your theory isn’t accurate) are the military discharges, to include the one with Airman Lovan last week. By necessity, I’d assume this failure mode would require a gun riding around in a holster without being manipulated (unloaded, slide racked, fired, etc) for some decently large chunk of time. I’d imagine a few days at minimum, likely longer. This is certainly plausible with civilian LE. On the military side of the house, it’s basically an impossibility, though. I guarantee you Airman Lovan had loaded that gun mere hours before the shooting. Hardly enough time for this failure mode to occur. That out of the way, we’ve seen no official report of the FE Warren shooting incident, so it’s hard to say with certainty exactly what happened. Many of the other military reports are heavily redacted and don’t include video footage, so once again, it leaves some questions unanswered. Your theory is certainly plausible and accounts for all of the variables, though. I’d be interested to see if someone could cook up a repeatable testing protocol to look into it more. I agree with your assessment. My explanation becomes more likely with time carried. However, it doesn’t mean a sufficiently large and “sticky” piece of debris which has properties lending itself to doing this couldn’t find its way there and potentially wedge itself in with a relatively few cycles and fire that day. Likewise, a pistol carried a lot and manipulated never didn’t necessarily catch that piece of debris weeks or months earlier… it just had a longer amount of time to catch it, and also a wider size range of contaminants to do their wedging action. Pistol could have been carried for months, and uncontaminated for months, and only caught a contaminant that day and then fired. It’s highly variable… as variable as foreign objects in the environment and how many times your elbow bumps your pistol. |
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I was just watching a video showing how the takedown lever moves a linkage that drops the sear for disassembly. I dont know shit about fuck how that works, but im putting my bet on that linkage having something to do with the uncommanded discharges. Because it's the I internet and everyone has an opinion.  |
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Quoted: Bottom line, for a lot of people like me, I wouldn’t touch one. I have a glock, 4 CZ’s, a 1911 and ruger.22. None of them have any problems. Oh, don’t get me wrong. I don’t own one, think the philosophical attitude towards safety inherent to the way the pistol is built is kind of negligent and irresponsible even in theory, and don’t think this thing is even worth fixing at this point it has had so many issues and is overall just a bad idea… I could go on. I do think figuring out why the thing goes off in holsters is meaningful so the same mistake isn’t repeated in the future. |
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Quoted: I was just watching a video showing how the takedown lever moves a linkage that drops the sear for disassembly. I dont know shit about fuck how that works, but im putting my bet on that linkage having something to do with the uncommanded discharges. Because it's the I internet and everyone has an opinion. I guess it could in theory… but if it can’t be repeated by that alone on a pistol that does it, then that can’t entirely be it. Might be yet one more contributing factor, but I think an unnecessary contributing factor. That might help it along but isn’t necessary for this to happen. |
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Quoted: Alternate theory is that the slide to frame fit has enough clearance on some guns for the sear to “walk” and release the striker over time. Every time the gun is racked the position and relationship of the sear and striker change in such an instance making testing a roll of the dice as to if the behavior is observed. One theory I’ve read is that if the sear is slow to rebound, the striker foot might catch only half of it, etc. |
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Quoted: One theory I’ve read is that if the sear is slow to rebound, the striker foot might catch only half of it, etc. Quoted: Quoted: Alternate theory is that the slide to frame fit has enough clearance on some guns for the sear to “walk” and release the striker over time. Every time the gun is racked the position and relationship of the sear and striker change in such an instance making testing a roll of the dice as to if the behavior is observed. One theory I’ve read is that if the sear is slow to rebound, the striker foot might catch only half of it, etc. Why is it slow to rebound? For this to be the case we have to explain why a P320 sear is slow to rebound but other pistols don’t have a slow rebounding sear. This isn’t an argument, it’s a question and justification for why the question matters. |
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Quoted: I was also thinking this maybe it's not fully engaged because they followed the slide forward while chambering a round Quoted: Quoted: One theory I've read is that if the sear is slow to rebound, the striker foot might catch only half of it, etc. That’s reasonable to think, but why doesn’t this affect other pistols like the M&P? And actually, it wouldn’t be the slide going forward slowly, it would be slide moving back only barely far enough for the sear and striker to barely slip past each other and not get full engagement because of that. You’d need to short-cycle, not just let it forward slowly. |
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Theory seems like something that should be studied. In this case the OP describes one would think the secondary notch would catch the striker leg and stop the forward movement. I can confirm the debris in the gun is possible. Back in 2016 or 2017 I was running the range when a Sgt's qualifying with his P320 fired one round and the pistol was locked up like a stuck casing. I had to put it in a vice and beat the slide back with a mallet. Finally got the gun apart and a white circle piece of paper from a hole punch was wadded up between the slide and barrel. We all were like how the hell did that get in there. I do wonder if the most recent upgrade made matters worse. Our first 320's in 2015 had triggers just like the classic line pistols. People on the internet complained that the trigger was stinging their fingers so Sig welded the back side of the trigger closed to get rid of the tuning fork effect. All of our 2016 and 2017 P320 shipments had the newer trigger. 2017 the drop video came out and December 2017 I was shipped 450 new pistols with the current upgrades. My understanding at the time was the upgrade was already in the works because the DoD drop test was from 8 feet and the P320 did not pass. It did pass the SAAMI 4 foot test for the original guns. The other interesting thing was in 2015 Law Enforcement had the option of the Glock style trigger safety in the P320 but no one purchased it so Sig dropped the option. I wonder if some of the original engineers of the P320 are currently thinking they should have kept the trigger safety all along. |
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Quoted: Theory seems like something that should be studied. In this case the OP describes one would think the secondary notch would catch the striker leg and stop the forward movement. I can confirm the debris in the gun is possible. Back in 2016 or 2017 I was running the range when a Sgt's qualifying with his P320 fired one round and the pistol was locked up like a stuck casing. I had to put it in a vice and beat the slide back with a mallet. Finally got the gun apart and a white circle piece of paper from a hole punch was wadded up between the slide and barrel. We all were like how the hell did that get in there. I do wonder if the most recent upgrade made matters worse. Our first 320's in 2015 had triggers just like the classic line pistols. People on the internet complained that the trigger was stinging their fingers so Sig welded the back side of the trigger closed to get rid of the tuning fork effect. All of our 2016 and 2017 P320 shipments had the newer trigger. 2017 the drop video came out and December 2017 I was shipped 450 new pistols with the current upgrades. My understanding at the time was the upgrade was already in the works because the DoD drop test was from 8 feet and the P320 did not pass. It did pass the SAAMI 4 foot test for the original guns. The other interesting thing was in 2015 Law Enforcement had the option of the Glock style trigger safety in the P320 but no one purchased it so Sig dropped the option. I wonder if some of the original engineers of the P320 are currently thinking they should have kept the trigger safety all along. That’s a lot of variables, and they are variables I am unfamiliar with in specifics. I think the P320 had a very easy to anticipate drop safety issue. It’s concerning that wasn’t caught before it ever left the drawing board, and certainly prototyping stage. It’s the 21st century not 1900. The a trigger safety would have stopped the drop problems, and would likely have mitigated some of the discharges that happen. However, neither of those prevent the firing avenue I propose in which I intend to explain the unexplainable. The P320 doesn’t only fire because of my OP explanation. It also fires because of obvious reasons like someone pulling the trigger by accident, big objects fouling the holster, etc. I can’t even pretend to explain every instance because there is no reasonable argument to be made they’re all by the exact same cause. I thank you for this additional information from your first hand experience and will have to see if any of that made changes to the internal geometry that would affect my hypothesis. |
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Quoted: I can't do that on my 3. 2 have manual safeties. The other is in a Flux Defense Raider chassis. Quoted: Quoted: If the slide goes slightly rearward, the firing pin will drop. I can't do that on my 3. 2 have manual safeties. The other is in a Flux Defense Raider chassis. It doesn't work on my M18, either. So far, mine passes all the tests, but I'm not carrying it anymore.
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