Cause of Sig P320 accidental discharges

**4V50 Gary** · May 11, 2025, 06:10 PM

Discussion about what is wrong with Sig P320.

1) Striker safety lever was designed to be a stamped part, but production boys decided to go MIM as it was $30 cheaper. MIM wears (and once the hardened surface is gone, it wears very quickly). If it is bent, that means engagement isn't right.
2) Wrong take down lever. Can't put a 40 take down lever in a 9mm as it raises "it" higher. Unsure of what "it" is but that means less sear contact.

https://www.youtube.com/watch?time_c...e_path=Mjg2NjY

I dunno as I've never handled a P320. Thoughts?

**Aguila Blanca** · May 11, 2025, 07:57 PM

I have received information regarding a serious malfunction of an M17 on a military range. I can't quote him or otherwise identify him. I will say that he now considers the design to be fatally flawed -- to the point that he is selling his personal P320.

mehavey · May 11, 2025, 09:06 PM

Quote:

....auto self-destruct of the pistol.

Can he/you give us a little more info ?
We've all heard about uncommanded firings, but I never heard about any blow-ups.

**Aguila Blanca** · May 12, 2025, 12:57 AM

Not a kaboom. He said the pistol "spontaneously disassembled itself." Most of the parts in the slide came out the back of the slide. The extractor went AWOL.

jmr40 · May 12, 2025, 07:30 AM

This is the 1st time I've seen any explanation of what may be happening. Problems can't be solved until they're identified. If this is the case, it's something that can easily be corrected.

tangolima · May 12, 2025, 02:20 PM

Changing manufacturing method of such small part saves $30? That's almost 10% of the selling price. 30 cents may be more credible.

MIM requires pretty high upfront setup cost. With volume it beats machining. But it probably will lose to stamping.

I don't think one can bend a MIM part without breaking it. MIM doesn't have hardened surface. It is good, or lousy, all the way through.

They need to change the crew.

-TL

Sent from my SM-N960U using Tapatalk

**4V50 Gary** · May 12, 2025, 04:53 PM

That raised my eyebrow too. It must be $30 per production run/batch.

It's my understanding that MIM is surface hardened and once that hardened surface is worn, the part wears quickly. We saw that with the Colt MK III Trooper that introduced "sintered" metal internal parts. Sintered has its advantages like lower cost precision parts.

I'm old fashioned and prefer forged/milled and filed, then cast (or stamping). I've heard of a MIM front sight falling apart. Classmate had to replace it with another front sight.

I can't watch this video which is an interview of a Sig Rep but the comments are gold.

https://youtu.be/NzHHUmqHA9k?feature=shared

TunnelRat · May 12, 2025, 05:26 PM

MIM can be done well. HK uses MIM in external controls and hammers, and those firearms go tens of thousands of rounds without parts breakages. Like anything, not all MIM is created equal.

**4V50 Gary** · May 12, 2025, 07:40 PM

TunnelRat - Yep. S&W revolvers' hammers and triggers have been MIM for a while.

Seven High · May 13, 2025, 08:50 AM

Is there a wide spread failure rate with the M17 & 18? Perhaps congress needs to get involved like they did with the M16.

tangolima · May 13, 2025, 01:31 PM

MIM is sintered metal powder. It is generally homogeneous, but it can be surfaces hardened afterwards. It is no different from stamping or milling in that regard.

Stamping is cheaper than MIM, excepted that it can't make elaborated 3d shapes. It would be silly to turn a stamped part into MIM.

Those guys on that video just mixed things up. Who are they BTW?

Can't have P320 behind enemy line in CA without paying through the nose, or I will get one to see for myself.

-TL

Sent from my SM-N960U using Tapatalk

Shoots Left · May 13, 2025, 01:36 PM

Call me skeptical but I can’t believe that if the issue with the P320 family is solely because of a manufacturing change to the striker safety that SIG would be fighting this so vigorously. It would appear to be an absurdly easy fix. Why from a business perspective would you plant your flag on this hill? As it stands SIG could lose millions in lawyer fees and lost judgements against them…and more importantly their reputation…over a faulty striker safety???

Personally I believe that there’s more to it than this and since everyone has their heels dug in real deep on this issue it’s gonna play out on way or another. If SIG comes out on the losing end of this, for whatever reason, it’s going to be an ugly loss IMO.

TunnelRat · May 13, 2025, 02:00 PM

In the video interview between Phil Strader (VP of Consumer Affairs for SIG) and the Military Arms Channel, SIG’s take seems to be that these events are the result of negligence on behalf of users as well as duty holsters that don’t completely block outside objects from intruding into the holster. I don’t remember if they actually say Safariland the company by name, but they mention the series of Safariland holsters by name. It’s an interesting take as they are seemingly shifting blame onto the largest provider of duty holsters in the US (as best as I know). I’m curious if SIG talked to Safariland before the interview.

At one point the Military Arms Channel asks why this isn’t happening with other pistols and those holsters. Strader’s response is that the P320 has exploded (no pun intended) in popularity after the M17 contract and with that growth in popularity more incidents will occur, unfortunately. I don’t necessarily disagree, but that doesn’t explain why the P320 itself seems to be having more issues than other polymer framed, striker fired pistols, which at this point have been on the market for decades, along with Safariland holsters.

**Aguila Blanca** · May 13, 2025, 06:55 PM

Has anyone watched the video of the unintended discharge in the police station in Connecticut? (Montville, CT, I think it was.) I have. Safariland duty holster. The gun was in the holster with the retention strap in place. Nobody went anywhere near the trigger or the butt. Someone brushed against the side of the holster and the gun discharged.

TunnelRat · May 13, 2025, 07:13 PM

Quote:

Originally Posted by Aguila Blanca

Has anyone watched the video of the unintended discharge in the police station in Connecticut? (Montville, CT, I think it was.) I have. Safariland duty holster. The gun was in the holster with the retention strap in place. Nobody went anywhere near the trigger or the butt. Someone brushed against the side of the holster and the gun discharged.

I believe they cover that incident in the video interview I mentioned. SIG seemed to argue that the officer’s keys at the front of his belt may have gotten in the trigger guard. I’d have to rewatch the video to make sure it was that incident.

**Aguila Blanca** · May 13, 2025, 09:09 PM

Quote:

Originally Posted by TunnelRat

I believe they cover that incident in the video interview I mentioned. SIG seemed to argue that the officer’s keys at the front of his belt may have gotten in the trigger guard. I’d have to rewatch the video to make sure it was that incident.

SIG may argue that, but seein' is believin'. I watched the video, multiple times. The pistol was fully in the holster, with the strap closed over the back end of the slide. The entire trigger window was fully within the holster. There's no way a key or keys got into the trigger guard.

TunnelRat · May 13, 2025, 09:10 PM

I’m not saying they’re right, I’m just relaying what they claimed about that incident.

I found the timestamp:

https://www.youtube.com/watch?v=NzHHUmqHA9k#t=15m48s

Duct Tape · May 14, 2025, 03:33 PM

For me, and I’m guessing many others, the damage is already done and any marketing campaign along the lines of Sig Sauer’s current approach only deepens it. It would have been more effective, at least to me who has purchased four new pistols in the past few weeks, if Sig had said we understand there is a problem and here is what we have done to address and correct it.

I’ve owned 226 and 220’s in the past, both excellent guns, and considered a new 229 and 365 but this time I’ve gone over to HK.

jmstr · May 17, 2025, 02:39 AM

Tangolima, there are now at least 2 Sig P320 models available for non LEO's to purchase here in California.

I am interested in the AD issue with the P320. I've got an Apex Trigger kit installed and wonder if this reduces the risk of an AD or if the same risk will always be there.

tangolima · May 17, 2025, 03:22 AM

Quote:

Originally Posted by jmstr

Tangolima, there are now at least 2 Sig P320 models available for non LEO's to purchase here in California.

I am interested in the AD issue with the P320. I've got an Apex Trigger kit installed and wonder if this reduces the risk of an AD or if the same risk will always be there.

You are right. Will watch out for deals. Thanks. Best price right now is around $600. It will be quite a sum after taxes and fees.

You can try the Glock test. Pistol unloaded with striker cocked. Carry it rough. Check whether the striker drops.

-TL

Sent from my SM-N960U using Tapatalk

**4V50 Gary** · May 26, 2025, 11:09 AM

This U-tuber identifies the problem with the out-of-spec disconnector lever (on trigger bar) and improper reassembly technique (supposed to lock the slide back, push the slide stop up first, push the release lever forward). Per the U-tuber reassembling it like glock may result in only partial sear contact.

https://youtu.be/utGmYit8YZA?si=V8npFonyZJkj065t

The above U-toober was inspired by this video by Three P20's in a Trenchcoat:

https://youtu.be/KuTxhHZ0uiA?si=dvRSGDSYabvsv3wB

I've no opinion as I've never seen, handled or examined a Sig P320.

stephen426 · May 29, 2025, 10:54 AM

I think Sig screwed the pooch with the P320 and is basically pointing the finger at everyone else. What other major gun manufacturer has had so many claims of "un-commanded" discharges? Glock had some where something was in the trigger guard when holstering, but I've never heard of one where the gun was fully in the holster and then gun going off.

I have a P320 X-Five (Pre-Legion) and was not impressed with it at all. It had a 6-6.5 lb. pull that was long and squishy. That is not my idea of a competition trigger. I switched it for a Gray Guns trigger and spring kit, and it is down to 2.5 lbs. now. I haven't had any issues with mine going off, but I don't carry it and I don't shoot it all that often. I did a class with it and it functioned fine for the 3 days I used it. That was about 400 - 500 rounds with holster work, movement, and rapid fire drills.

Shoots Left · May 29, 2025, 03:45 PM

Have any of these YouTube “Subject Matter Experts” been called on to testify on behalf of any of the plaintiffs?

May 11, 2025, 06:10 PM	#1
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	Cause of Sig P320 accidental discharges Discussion about what is wrong with Sig P320. 1) Striker safety lever was designed to be a stamped part, but production boys decided to go MIM as it was $30 cheaper. MIM wears (and once the hardened surface is gone, it wears very quickly). If it is bent, that means engagement isn't right. 2) Wrong take down lever. Can't put a 40 take down lever in a 9mm as it raises "it" higher. Unsure of what "it" is but that means less sear contact. https://www.youtube.com/watch?time_c...e_path=Mjg2NjY I dunno as I've never handled a P320. Thoughts? __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 11, 2025, 07:57 PM	#2
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 19,034	I have received information regarding a serious malfunction of an M17 on a military range. I can't quote him or otherwise identify him. I will say that he now considers the design to be fatally flawed -- to the point that he is selling his personal P320. __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

May 12, 2025, 12:57 AM	#4
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 19,034	Not a kaboom. He said the pistol "spontaneously disassembled itself." Most of the parts in the slide came out the back of the slide. The extractor went AWOL. __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

May 12, 2025, 07:30 AM	#5
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,972	This is the 1st time I've seen any explanation of what may be happening. Problems can't be solved until they're identified. If this is the case, it's something that can easily be corrected. __________________ "If you're still doing things the same way you were doing them 10 years ago, you're doing it wrong" Winston Churchill

May 12, 2025, 04:53 PM	#7
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	That raised my eyebrow too. It must be $30 per production run/batch. It's my understanding that MIM is surface hardened and once that hardened surface is worn, the part wears quickly. We saw that with the Colt MK III Trooper that introduced "sintered" metal internal parts. Sintered has its advantages like lower cost precision parts. I'm old fashioned and prefer forged/milled and filed, then cast (or stamping). I've heard of a MIM front sight falling apart. Classmate had to replace it with another front sight. I can't watch this video which is an interview of a Sig Rep but the comments are gold. https://youtu.be/NzHHUmqHA9k?feature=shared __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 12, 2025, 02:20 PM	#6
tangolima Senior Member Join Date: September 28, 2013 Posts: 5,122	Changing manufacturing method of such small part saves $30? That's almost 10% of the selling price. 30 cents may be more credible. MIM requires pretty high upfront setup cost. With volume it beats machining. But it probably will lose to stamping. I don't think one can bend a MIM part without breaking it. MIM doesn't have hardened surface. It is good, or lousy, all the way through. They need to change the crew. -TL Sent from my SM-N960U using Tapatalk

May 12, 2025, 05:26 PM	#8
TunnelRat Senior Member Join Date: May 22, 2011 Posts: 12,413	MIM can be done well. HK uses MIM in external controls and hammers, and those firearms go tens of thousands of rounds without parts breakages. Like anything, not all MIM is created equal.

May 12, 2025, 07:40 PM	#9
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	TunnelRat - Yep. S&W revolvers' hammers and triggers have been MIM for a while. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 13, 2025, 08:50 AM	#10
Seven High Senior Member Join Date: December 11, 2004 Posts: 663	Is there a wide spread failure rate with the M17 & 18? Perhaps congress needs to get involved like they did with the M16.

May 13, 2025, 01:31 PM	#11
tangolima Senior Member Join Date: September 28, 2013 Posts: 5,122	MIM is sintered metal powder. It is generally homogeneous, but it can be surfaces hardened afterwards. It is no different from stamping or milling in that regard. Stamping is cheaper than MIM, excepted that it can't make elaborated 3d shapes. It would be silly to turn a stamped part into MIM. Those guys on that video just mixed things up. Who are they BTW? Can't have P320 behind enemy line in CA without paying through the nose, or I will get one to see for myself. -TL Sent from my SM-N960U using Tapatalk Last edited by tangolima; May 13, 2025 at 01:39 PM.

May 13, 2025, 01:36 PM	#12
Shoots Left Senior Member Join Date: November 22, 2024 Location: Southeast Texas Posts: 120	Call me skeptical but I can’t believe that if the issue with the P320 family is solely because of a manufacturing change to the striker safety that SIG would be fighting this so vigorously. It would appear to be an absurdly easy fix. Why from a business perspective would you plant your flag on this hill? As it stands SIG could lose millions in lawyer fees and lost judgements against them…and more importantly their reputation…over a faulty striker safety??? Personally I believe that there’s more to it than this and since everyone has their heels dug in real deep on this issue it’s gonna play out on way or another. If SIG comes out on the losing end of this, for whatever reason, it’s going to be an ugly loss IMO.

May 13, 2025, 02:00 PM	#13
TunnelRat Senior Member Join Date: May 22, 2011 Posts: 12,413	In the video interview between Phil Strader (VP of Consumer Affairs for SIG) and the Military Arms Channel, SIG’s take seems to be that these events are the result of negligence on behalf of users as well as duty holsters that don’t completely block outside objects from intruding into the holster. I don’t remember if they actually say Safariland the company by name, but they mention the series of Safariland holsters by name. It’s an interesting take as they are seemingly shifting blame onto the largest provider of duty holsters in the US (as best as I know). I’m curious if SIG talked to Safariland before the interview. At one point the Military Arms Channel asks why this isn’t happening with other pistols and those holsters. Strader’s response is that the P320 has exploded (no pun intended) in popularity after the M17 contract and with that growth in popularity more incidents will occur, unfortunately. I don’t necessarily disagree, but that doesn’t explain why the P320 itself seems to be having more issues than other polymer framed, striker fired pistols, which at this point have been on the market for decades, along with Safariland holsters.

May 13, 2025, 06:55 PM	#14
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 19,034	Has anyone watched the video of the unintended discharge in the police station in Connecticut? (Montville, CT, I think it was.) I have. Safariland duty holster. The gun was in the holster with the retention strap in place. Nobody went anywhere near the trigger or the butt. Someone brushed against the side of the holster and the gun discharged. __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

May 13, 2025, 09:10 PM	#17
TunnelRat Senior Member Join Date: May 22, 2011 Posts: 12,413	Cause of Sig P320 accidental discharges I’m not saying they’re right, I’m just relaying what they claimed about that incident. I found the timestamp: https://www.youtube.com/watch?v=NzHHUmqHA9k#t=15m48s Last edited by TunnelRat; May 13, 2025 at 09:17 PM.

May 14, 2025, 03:33 PM	#18
Duct Tape Junior Member Join Date: April 30, 2025 Posts: 5	For me, and I’m guessing many others, the damage is already done and any marketing campaign along the lines of Sig Sauer’s current approach only deepens it. It would have been more effective, at least to me who has purchased four new pistols in the past few weeks, if Sig had said we understand there is a problem and here is what we have done to address and correct it. I’ve owned 226 and 220’s in the past, both excellent guns, and considered a new 229 and 365 but this time I’ve gone over to HK.

May 17, 2025, 02:39 AM	#19
jmstr Senior Member Join Date: February 24, 2001 Location: San Joaquin Valley, CA Posts: 1,303	Tangolima, there are now at least 2 Sig P320 models available for non LEO's to purchase here in California. I am interested in the AD issue with the P320. I've got an Apex Trigger kit installed and wonder if this reduces the risk of an AD or if the same risk will always be there.

May 26, 2025, 11:09 AM	#21
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	This U-tuber identifies the problem with the out-of-spec disconnector lever (on trigger bar) and improper reassembly technique (supposed to lock the slide back, push the slide stop up first, push the release lever forward). Per the U-tuber reassembling it like glock may result in only partial sear contact. https://youtu.be/utGmYit8YZA?si=V8npFonyZJkj065t The above U-toober was inspired by this video by Three P20's in a Trenchcoat: https://youtu.be/KuTxhHZ0uiA?si=dvRSGDSYabvsv3wB I've no opinion as I've never seen, handled or examined a Sig P320. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 29, 2025, 10:54 AM	#22
stephen426 Senior Member Join Date: March 11, 2005 Posts: 3,879	I think Sig screwed the pooch with the P320 and is basically pointing the finger at everyone else. What other major gun manufacturer has had so many claims of "un-commanded" discharges? Glock had some where something was in the trigger guard when holstering, but I've never heard of one where the gun was fully in the holster and then gun going off. I have a P320 X-Five (Pre-Legion) and was not impressed with it at all. It had a 6-6.5 lb. pull that was long and squishy. That is not my idea of a competition trigger. I switched it for a Gray Guns trigger and spring kit, and it is down to 2.5 lbs. now. I haven't had any issues with mine going off, but I don't carry it and I don't shoot it all that often. I did a class with it and it functioned fine for the 3 days I used it. That was about 400 - 500 rounds with holster work, movement, and rapid fire drills. __________________ The ATF should be a convenience store instead of a government agency!

May 29, 2025, 03:45 PM	#23
Shoots Left Senior Member Join Date: November 22, 2024 Location: Southeast Texas Posts: 120	Have any of these YouTube “Subject Matter Experts” been called on to testify on behalf of any of the plaintiffs?