Gunsmith here, let me give you a near definitive explanation to why this is happening since nobody seems to know how to explain things in a coherent manner.
TL:DR 1. Sigs QC has diminished significantly. Too many load bearing components are MIM, and to bad specs. 2. The striker safety is being defeated very easily and likely, once partially disabled, it is getting defeated by just the simple inertia of the striker itself. 3. Nearly every p320 out there DOES NOT have this issue, HOWEVER, there are AT LEAST hundreds if not thousands out in circulation that are indeed dangerous. Test yours. 4. Brass fouling, debris, and carbon fouling is likely taking up that 1mm of travel that is disabling the safety just enough for the strikers inertia alone to overcome the rest of the safety travel 5. Lastly, the sear surfaces are not polished and smoothed, so the sear can perch. When officers and military servicemen have the pews moving around in the holster, the sear surfaces can climb one another, and when the pew is drawn from a holster or put back in OR DROPPED ON A DESK, it can fire. 6. LASTLY: IF YOUR SLIDE TO FRAME FITMENT IS LOOSE AND WOBBLY, FIX IT OR GET RID OF IT!!!!!!!!!!!!!
For the in depth explanation, FIRST, we need to go over some machining/engineering/gunsmithing terms so we know what we are talking about here.
OD: outer diameter measurement ID: inner diameter measurement TOLERANCE SPECIFICATION RANGES (tolerance specs): the acceptable range of dimensions that the pew can function with, typically within a range of +-5 thousandths of an inch (for pew parts)
TOLERANCE STACKING: when multiple parts are undersized or oversized in combination with one another and it creates a fault point. FACTOR OF SAFETY: the ratio of the ultimate stress of a material or structure to the maximum stress it is expected to bear during normal operation. SEAR PERCHING: where the sear surface meets the striker leg, there is uneven surfaces. If your sear surfaces have catches, burrs, scratches, or any surface blemishes and are not polished, they can catch and hang. If you pull your trigger most of the way but let it go to cancel your shot, you run the risk of sear perching: the sear might not go back to full positive engagement. Hanging on the cliffs edge, so to speak. POSITIVE AND NEGATIVE ENGAGEMENT:(see photo) The angles of the sear contact surfaces. Positive engagement means that if you were to bump it or stop pulling the trigger, the sears want to ramp down each other and force more surface area contact. Negative engagement is the opposite. If you were to bump it or you stopped pulling the trigger,, the sears will hold position or in worse cases, actually slide up each other and slip off.
With this out of the way, let me give you a an in depth explanation.
Outright, This is blatantly a tolerance stacking issue. As shown (but not well explained) by @WashingtonGunProject The screw is only there to be a OD-calibrated COMMONLY AVAILABLE tool for YOU to test your on P320 at home. So let’s get that “wElL jUsT don’t ShOvE a ScReW In ThErE” argument out of the way.
For this tolerance stacking issue to occur, There is poorly engineered tolerance specs from the designers schematics OR the Quality control is so bad that the parts are just too far out of spec or the wrong parts are installed(wrong striker safety caliber).
In Washington gun projects video, he shows that on a confirmed BAD sig p320, his striker safety can be disabled with less than 1 mm trigger pre travel. THAT is a pistol that has came FROM sigs factory in this condition. That is completely unacceptable. We are talking about pre travel that is LESS than the OD of mechanical pencil lead, DUDES. I can measure the carbon buildup in my pews and get somewhere near that. Not to account for brass shavings and fouling as well.
Design flaws: If you look at the striker safety, the front edge is RADIUSED WITH NEGATIVE ENGAGEMENT!!!! This is so asinine. This is why the striker can be partially disabled and the spring pressure can just cause the striker safety to travel up the rest of the way.
The p320 needs a trigger safety (trigger dingus), this would nearly eliminate the potential of an ND or a holster related trigger pull. The industry proved that this is a necessity on striker pistols.
Too many MIM’d load bearing, critical parts in the pew. FBI and military concluded that striker safeties were breaking. Thats unacceptable.
The slop between the slide and fame allows the sears to have excessive play and over a full day in a holster, they can get jostled and the sear can walk and perch.
CONCLUSION: cops and others are having holsters torque the slides with the aforementioned tolerance stacking issues and defeated safeties. Slide gets torqued, sears disengage, and p320 goes pew.
Exandria Official
Gunsmith here, let me give you a near definitive explanation to why this is happening since nobody seems to know how to explain things in a coherent manner.
TL:DR
1. Sigs QC has diminished significantly. Too many load bearing components are MIM, and to bad specs.
2. The striker safety is being defeated very easily and likely, once partially disabled, it is getting defeated by just the simple inertia of the striker itself.
3. Nearly every p320 out there DOES NOT have this issue, HOWEVER, there are AT LEAST hundreds if not thousands out in circulation that are indeed dangerous. Test yours.
4. Brass fouling, debris, and carbon fouling is likely taking up that 1mm of travel that is disabling the safety just enough for the strikers inertia alone to overcome the rest of the safety travel
5. Lastly, the sear surfaces are not polished and smoothed, so the sear can perch. When officers and military servicemen have the pews moving around in the holster, the sear surfaces can climb one another, and when the pew is drawn from a holster or put back in OR DROPPED ON A DESK, it can fire.
6. LASTLY: IF YOUR SLIDE TO FRAME FITMENT IS LOOSE AND WOBBLY, FIX IT OR GET RID OF IT!!!!!!!!!!!!!
For the in depth explanation,
FIRST, we need to go over some machining/engineering/gunsmithing terms so we know what we are talking about here.
OD: outer diameter measurement
ID: inner diameter measurement
TOLERANCE SPECIFICATION RANGES (tolerance specs): the acceptable range of dimensions that the pew can function with, typically within a range of +-5 thousandths of an inch (for pew parts)
TOLERANCE STACKING: when multiple parts are undersized or oversized in combination with one another and it creates a fault point.
FACTOR OF SAFETY: the ratio of the ultimate stress of a material or structure to the maximum stress it is expected to bear during normal operation.
SEAR PERCHING: where the sear surface meets the striker leg, there is uneven surfaces. If your sear surfaces have catches, burrs, scratches, or any surface blemishes and are not polished, they can catch and hang. If you pull your trigger most of the way but let it go to cancel your shot, you run the risk of sear perching: the sear might not go back to full positive engagement.
Hanging on the cliffs edge, so to speak.
POSITIVE AND NEGATIVE ENGAGEMENT:(see photo)
The angles of the sear contact surfaces. Positive engagement means that if you were to bump it or stop pulling the trigger, the sears want to ramp down each other and force more surface area contact.
Negative engagement is the opposite. If you were to bump it or you stopped pulling the trigger,, the sears will hold position or in worse cases, actually slide up each other and slip off.
With this out of the way, let me give you a an in depth explanation.
Outright, This is blatantly a tolerance stacking issue. As shown (but not well explained) by @WashingtonGunProject
The screw is only there to be a OD-calibrated COMMONLY AVAILABLE tool for YOU to test your on P320 at home.
So let’s get that “wElL jUsT don’t ShOvE a ScReW In ThErE” argument out of the way.
For this tolerance stacking issue to occur,
There is poorly engineered tolerance specs from the designers schematics OR the Quality control is so bad that the parts are just too far out of spec or the wrong parts are installed(wrong striker safety caliber).
In Washington gun projects video, he shows that on a confirmed BAD sig p320, his striker safety can be disabled with less than 1 mm trigger pre travel.
THAT is a pistol that has came FROM sigs factory in this condition. That is completely unacceptable. We are talking about pre travel that is LESS than the OD of mechanical pencil lead, DUDES.
I can measure the carbon buildup in my pews and get somewhere near that. Not to account for brass shavings and fouling as well.
Design flaws:
If you look at the striker safety, the front edge is RADIUSED WITH NEGATIVE ENGAGEMENT!!!! This is so asinine. This is why the striker can be partially disabled and the spring pressure can just cause the striker safety to travel up the rest of the way.
The p320 needs a trigger safety (trigger dingus), this would nearly eliminate the potential of an ND or a holster related trigger pull. The industry proved that this is a necessity on striker pistols.
Too many MIM’d load bearing, critical parts in the pew.
FBI and military concluded that striker safeties were breaking. Thats unacceptable.
The slop between the slide and fame allows the sears to have excessive play and over a full day in a holster, they can get jostled and the sear can walk and perch.
CONCLUSION: cops and others are having holsters torque the slides with the aforementioned tolerance stacking issues and defeated safeties. Slide gets torqued, sears disengage, and p320 goes pew.
4 months ago | [YT] | 3