You have an extreme loathing for the Sig P320, I’m unfamiliar with what it did
HOOOOOOO HERE WE GO
THE BEGINNING
Okay so, the P320 has been around since 2014, when it got revealed at SHOT Show (biiiiig gun industry trade show, kinda the E3 or GenCon of the American gun industry.) It's big selling point in 2014 was the "fire control unit". What is that? Well, lemme show you.
When it comes to the P320, THIS is not legally a gun:
THIS is:
The internal trigger/safety/control group is a single modular part. This part is the actual registered legal firearm. Everything else on the pistol (slide, frame, magazine, barrel, optics plate, etc) does not legally count as a controlled item.
This means that every other part of the weapon can be swapped out with other components without any legal issues. Want a full size duty grip in like six different colors? SIG will sell you that.
Feel like switching to a shorter slide? You can do that without having to buy a new gun, just a slide.
Want to take your pistol and turn it into a compact semi-auto PDW? You can do that too!
The FCU is removable as a single piece, so you can move it between entirely different setups at will.
The FCU-as-registered-firearm concept was (at the time) a pretty big deal. Pistols hadn't had that level of sheer easy customization before. Rifles had had it for a long time, for pistols it was fairly new.
If it had stayed there, things probably would have been okay for SIG.
But it didn't.
MHS
The trouble starts off with the P320 getting attention for being an entrant into the Army MHS (Modular Handgun System) contract in 2015-2016. This was a massive contract, aiming to replace the Army's 30-year-old Beretta M9s (and to a lesser extent the compact SIG M11) with a new, lighter, more modern, higher capacity handgun. The old guns were wearing out and they needed new ones - fairly normal procedure. The Marines also participated in the trials because they were interested as well.
The official competition began in August 2015. There were 12 initial entrants:
Italy: Beretta APX chambered in 9mm NATO and .40 S&W.
Czech Republic: CZ P-07 MHS and P-09 MHS chambered in 9 mm NATO and .40 S&W.
Belgium: FN Herstal FN FNS variant, from which the FN 509 Tactical was developed.
Austria: Glock 17 MHS and 19 MHS chambered in 9 mm NATO, and the Glock 22 MHS and 23 MHS chambered in .40 S&W, respectively.
United States: KRISS USA Sphinx SDP variant chambered in 9mm NATO.
United States: SIG Sauer P320 MHS, a variant of the P320.
United States: Smith & Wesson M&P M2.0; in co-operation with General Dynamics Ordnance and Tactical Systems.
United States: STI and Detonics Defense STX.
By late 2016, they'd down-selected to two finalists: SIG and Glock. After that there was to be a Product Verification Test - essentially torture testing the guns to see how they performed. The PVT was to include environmental testing as well as a twenty-two thousand five hundred round endurance test (meaning they were going to fire that many rounds through the trials sample handguns to determine their durability and reliability).
SCANDAL
On 19 January 2017, the Army announced that SIG had won the competition.
One small problem.
They never even started the PVT.
We know this because Glock immediately (in legal timeframe terms) filed a protest with the US Government Accountability Office on 24 February 2017 (this protest was denied in June that year).
Now why did this happen? Couple of reasons have been speculated. One - SIG massively underbid for the contract compared to Glock. Two - it is quite common for retired military officers to go into the firearms sector after retirement. Allegedly, an Army procurement officer did just that, and ended up with SIG. Riiiiiiiight around the time of the MHS competition. ;)
PROLIFERATION
Anyway, SIG had won*, so the Army placed their order, and soon after, so did every US military branch (iirc the Coast Guard held out longest), and soon the M17 and M18 were officially adopted - the M18 being the compact version of the full size M17.
Tons of organizations adopted this gun - because if it was good enough for the largest military in the world, it had to be good, right?
There's even more on the list, but image limits...
(note: Ukraine's M18s were donated as defense aid, they did not officially adopt it, and the numbers of M18s there is relatively small)
And then the problems began.
OOPS, ALL MALFUNCTIONS!
Post-adoption testing and several real world incidents showed that the P320 had a disturbingly common tendency to fire ("discharge" in gun speak) if dropped on the ground at certain angles - in gun-speak terms it was not "drop safe". Some independent testing (the Army did their own tests ofc but we don't have those documents) showed up to a 40% rate of discharge when dropped from common heights and angles (e.g. falling out of a holster, slipping out of someone's hand, etc). The big "oh fuck" moment came when the Dallas Police Department issued orders for all officers to cease carrying the P320 until their own investigations were completed. Less than a month later SIG promised they'd found the cause of the issue and would fix it.
They mostly succeeded - but not entirely. Since 2017, there have still been reports of P320s being not drop-safe, and six other police departments have removed it from service. A note of nuance: SIG's fix was not a recall, so not every P320 may have been updated. The fact that the number of drop firing instances has diminished significantly would indicate that the fix seems to have worked on the guns that did get upgraded.
But we're not done yet.
The Canadian JTF2 special forces unit (Canada's equivalent to Delta Force) - the only CAF unit to adopt the P320 - had a misfire incident where one of their troops got injured - to quote: "a partial depression of the trigger by a foreign object combined with simultaneous movement of the slide [...] that then allowed a round to be fired whilst the pistol was still holstered" ... the usage of a holster designed for a different pistol was a contributory factor; the P320 itself was not at fault nor were there any issues with how it had been procured by Canadian defence officials (since questions had been raised as to whether these officials were aware of the drop safety issues.)"
The P320 wasn't the culprit this time, but other incidents of the gun misfiring have been reported.
This all seems bad for SIG, yeah?
IT GETS WORSE
We're still not done.
In 2023, the Washington Post published an investigation in which more than 100 people reported that their P320 had fired without any trigger pressure, and that at least 80 of those people had been injured as a result.
This pistol can fire without anyone touching the trigger.
How? Well, that comes down to the P320's design. It is a striker fired handgun, based on the earlier Sig P250.
WTF DOES THAT MEAN?
In (nearly) every modern gun ever there is a firing pin. This is a pointy bit of metal that impacts the primer (a small explosive charge) embedded into the base of a cartridge, setting off the rest of the gunpowder and propelling the projectile out the barrel.
In order for the gun to be safe, the firing pin is held back, away from the primer, until the trigger is pulled.
In traditional (i.e. older) handgun designs, rhe method of getting the firing pin to contact the primer was the hammer. This is that thing you sometimes see people pull back on a pistol in movies to make one of the stock Dramatic Gun Noises™. What they're doing is pulling the hammer back into a cocked position, which either makes the gun ready to fire, or on some modern guns, makes it take less force to pull the trigger. In a hammer-fired gun, the firing pin rests a few millimeters (if that) back from the primer. When the trigger is pulled, the hammer flies forward, hitting the firing pin and causing the pin to contact the primer (on some really old models, the hammer IS the firing pin). The firing pin cannot move far enough forward to fire the bullet without the smack from the hammer. There's way more nuance to this, but that's basically how it works.
In more modern times, striker fired handguns have become popular as well. In a striker fired gun, once cocked by racking the slide, the firing pin is held back by a rather strong spring. This spring is released by pulling the trigger, freeing the firing pin to shoot forward and strike the primer.
How does this relate to the P320?
Most striker fired guns use the pull of the trigger as a safety mechanism. The striker is not fully cocked until the trigger is pulled. Basically most striker fired guns have the striker sitting about 90% cocked, with the final 10% of that completed by pulling the trigger. This is why striker fired guns have (on average) heavier, harder to pull triggers than hammer fired guns - on a hammer gun, you're simply tilting a block out of the way to release the hammer, while on a striker fired gun, you are compressing a spring.
SIG, though... SIG wanted a good trigger in their P320.
THE STUPID
The P320's striker is not a typical striker mechanism.
In the P320, the striker is essentially ALWAYS at full cock, and only needs to be released by the trigger.
So you now have a gun that is essentially way easier to shoot - whether you want to not.
Now, most military versions of the SIG P320 have manual safeties, which block the trigger from moving. Civilian P320s have this as an optional feature - they don't come with manual safeties from the factory.
And it turns out that if you have a gun that is one good jolt or odd movement away from being fired, it tends to have what are euphemistically known as "uncommanded discharges".
It goes off on its own.
This has led to numerous instances of people shooting themselves in the leg, or accidentally shooting others. Even while the pistol was in its holster.
Even with the safety on.
Earlier this month, Airman Brayden Lovan, a 21-year old US Air Force airman at F. E. Warren AFB died after his M18 pistol fired on its own. Allegedly, he removed his Safariland holster (the official holster designed for the P320 during the MHS competition - this was not a case like with JTF2 earlier) from his belt, and placed on a table. The gun then went off, hitting him in the chest, killing him immediately or shortly thereafter. NOTE: This was not in fact an uncommanded discharge. Airman Lovan was murdered by another Air Force airman, who proceeded to deflect blame (for a time) by blaming the M18 itself.
The Air Force Global Strike Command issued an immediate pause on use of the M18, which soon expanded to all USAF Air Combat Commands.
What's more, in August 2024, the FBI Ballistics Research Facility issued a report on an investigation into another uncommanded discharge, this one having occurred to a Michigan State Police officer. According to the report, the internal safety mechanisms of the P320 could be rendered inoperable “with movements representing those common to a law enforcement officer." A copy of this report was obtained and came to public light a few weeks ago, thanks to a FOIA request to Michigan State Police.
According to the report, the Michigan State Police began transitioning its officers from department-issued Glock pistols to Sig Sauer M18s in April 2024. Notably, the department experienced “dead” trigger issues in the M18s that Sig Sauer delivered, meaning that the weapons failed to fire when the trigger was pulled and/or would not reset. Sig determined the triggers were “out of spec”, and so 0.020” was ground off, and the company largely installed the new triggers itself.
After receiving his issue of a Sig M18, the report says an unnamed officer conducted training consisting of a 1,200-round course of fire, cleaned his pistol, and fired about another 100 rounds during an open range session in mid-July 2024. On July 31, 2024, the officer conducted approximately three presentation drills from his department-issued Alien Gear Rapid Force Level 3 holster to practice acquiring his Sig Sauer Romeo M17 red dot; the M18 pistol was also equipped with a Surefire X300 Turbo light.
Several minutes later, the officer walked into and stood in a squad area with other officers when his M18 fired, uncommanded. The officer had objects in his hands at the time of the firing, including his keys, and statements from others present attest that the officer did not press his pistol’s trigger. The officer was not injured.
SO WHAT DOES ALL THIS MEAN?
SIG is fucked, basically. Their PR department is issuing denial after denial that their product is flawed, insisting it meets safety standards.
But the damage is much more than just mechanical. Even if SIG manages to find the cause the issue and fix it, their reputation is done. People have been injured and killed by the P320, and it has become a (very morbid) laughingstock in the process. I will allow Ian McCollum of Forgotten Weapons to discuss this:
So, in conclusion:
don't buy a P320.
