Another SIG 320 fires while holstered- SIG agreed to buy all the departments 320s back

I got the press release of SIG saying it ends today- and told us that some/ many holsters some/ many weapons lights some/ many aftermarket triggers and some ammo can cause uncommanded discharges and those aftermarket lights holsters and ammo created “user error discharges “
And I saw the post someone had an early 320 owners manual that said the safest way to carry the 320 was with the chamber empty.

Recalls , lawsuits and buybacks don’t sound like a one off problem.
 


I did a quick google fu search- and stopped counting after 80 mostly well documented incidents of a 320 firing while in the holster.

Did a similar search for “Hi Point fires while holstered “. And all results were for Sig firing while holstered .
 
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The fix.
 
For those of us who don't have one of these particular make/model's, can anyone summarize as to what "the problem" actually is?

cheetoh dust?
There are two different problems.

First, OOB detonations causing the grip module to blow up. This is thought to be caused primarily by the disconnector that connects before the action is in battery, and a barrel with an unsupported chamber. The chamber problem is similar to early Glock, and I've read to a worse extent. Apparently the disconnector wears with use and makes this more likely.

The second problem is the uncommanded discharge. To my knowledge, the exact cause of this is not fully known. From what I have read, it's likely cause is a multitude of manufacturing issues. First, many of the parts are MIM and when viewed under a microscope, are rather rough. Along with this, allegedly the QA/QC is sub-par, many of the parts made in India, and tolerance stacking becomes an issue. Second, another theory I've read is that between the cast, not forged, FCU chassis, and the polymer grip module, pressure on the frame & slide can, in conjunction with tolerance stacking, cause them to twist/deform slightly and release the striker.

For awhile the UD was allegedly to be related to a specific Safariland holster that put too much pressure on the side of the slide, but the UDs have continued with other holsters.

ETA: More recently I've seen speculation that dirty guns can exacerbate the tolerance stacking issues and are potentially more prone to UDs.

Obligatory: I don't know anything about manufacturing, small arms design or gunsmithing. This is all what I've read from 3rd parties as a p320 owner.
 
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There are two different problems.

First, OOB detonations causing the grip module to blow up. This is thought to be caused primarily by the disconnector that connects before the action is in battery, and a barrel with an unsupported chamber. The chamber problem is similar to early Glock, and I've read to a worse extent. Apparently the disconnector wears with use and makes this more likely.

The second problem is the uncommanded discharge. To my knowledge, the exact cause of this is not fully known. From what I have read, it's likely cause is a multitude of manufacturing issues. First, many of the parts are MIM and when viewed under a microscope, are rather rough. Along with this, allegedly the QA/QC is sub-par, many of the parts made in India, and tolerance stacking becomes an issue. Second, another theory I've read is that between the cast, not forged, FCU chassis, and the polymer grip module, pressure on the frame & slide can, in conjunction with tolerance stacking, cause them to twist/deform slightly and release the striker.

For awhile the UD was allegedly to be related to a specific Safariland holster that put too much pressure on the side of the slide, but the UDs have continued with other holsters.

Obligatory: I don't know anything about manufacturing, small arms design or gunsmithing. This is all what I've read from 3rd parties as a p320 owner.

There’s a video you can test if your P320 is more at risk of dropping the striker


The other thing I’ve seen is that if you get it out of battery slightly, with some combinations of factors when the slide goes back in the battery (maybe due to shifting weight, side impact, etc) it drops the striker. So if you had a holster that maybe didn’t quite fit perfectly and could put pressure on the wml and slightly unlock the slide, you’d be at risk of UD.

All in all it’s very rare but it’s also very real.
 
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dropping HGs is not a recommended action. i have never heard of a pistol with a grip safety firing when it is not activated by the gun being in hand. guess anything is possible. might be a paranoia issue buy when carrying with the gun pointed at the rt nut,i am just much happier having a GS.
 
dropping HGs is not a recommended action. i have never heard of a pistol with a grip safety firing when it is not activated by the gun being in hand. guess anything is possible. might be a paranoia issue buy when carrying with the gun pointed at the rt nut,i am just much happier having a GS.

No matter the number of “safeties’” idiots will always find a way to defeat them.
 
I don't think that I've seen it mentioned yet, but doesn't the Sig P320 pre-cock its striker "more" than other striker fired handguns? Wasn't this done deliberately to get a better trigger feel?
 
I don't think that I've seen it mentioned yet, but doesn't the Sig P320 pre-cock its striker "more" than other striker fired handguns? Wasn't this done deliberately to get a better trigger feel?
Yes and no. Yes it has a fully cocked striker but so does the PDP and VP9 and they don’t ND.
But the PDP and VP9 have trigger dingus and a the PDP has a firing pin block similar to the Glock.
The 320 doesn’t have the trigger dingus (although not sure it makes a significant difference) and doesn’t have a traditional channel firing pin block. And that’s the issue, it’s about the right combination of some element of the design and some failure in the QC/QA process and then some kind of external element ie: shifting weight or holstering or side impact. Short of a full re-engineering/recall it’s still cheaper for now for Sig to payout + NDA and probably look at increasing QC to minimize the issue. Plus the legal exposure alone would probably bankrupt Sig if they ever admitted their design was unsafe.

Honestly digging into the P320, you see how much Gaston was ahead of its time. Absolute genius design.
 
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