WSC list of Supporting Documents regarding Sig P320 –
∙ WSC Memorandum to Board of Director “Evolving Situation of Sig Sauer P-320 Pistol” ∙ FBI Forensic Evaluation Report on Sig Sauer P320
∙ US Homeland Security ICE Remove SIG P320 from Service
∙ Gunsite Academy P320 Prohibition ∙ Pima Pistol Club Bans SIG P320
Williams Sportsman’s Club
PO Box 131 Williams AZ 86046-0131
www.williamssportsmansclub.com
wscazrange01@gmail.com
M E M O R A N D U M
Date: Aug 11, 2025
From: Bruce Speirs, VP
To: All Board Members & Range Safety Officers
Subject: Evolving Situation of Sig Sauer P-320 Pistol
Executive Brief –
In 2023, a WSC member was severely injured when his Sig P-320 discharged. This incident was one of what would become ongoing and ever increasing occurrences with this pistol across the country involving law enforcement personnel and shooting sports enthusiasts. The WSC initially banned the pistol from range use in late 2024; however this was rescinded after some push back by a few WSC members that thought this action was initiated without sufficient data.
Current Situation –
Information most recently released by two Federal Law Enforcement agencies, the US Marine Corps, the Gunsight Academy, and the Pima Gun Club in the last week, has significantly changed the status of the SIG P320 pistol and its military variants M17 & M18 as follows.
The first action was the Department of Homeland Security which ordered the immediate removal from service all SIG P320 pistols and their replacement with Glock 19 9mm pistols – refer to attached memorandum.
This action followed the public release of a very detailed forensic examination report of a SIG M18 pistol as submitted to the Federal Bureau of Investigation, Ballistics Research Facility, which was concluded in August 2024. The report was considered a sensitive, ‘Not for public release’ report and was only released after a Freedom of Information Act (FOIA) request is also attached.
The United States Marine Corps has ordered an engineering review of the Sig M18 after an investigation determined the M18 was on safe and secure in its holster when it discharged. The investigation further recommended that all USMC personnel required to carry the weapon do so with a loaded magazine but without a live round in the chamber.
The world renowned Gunsight Academy – see attached statement – and the Pima Gun Club have now banned the SIG P320 in response to the growing uncertainty of its safety.
The cumulative effect of all this new information now provides substantive authoritative guidance and a preponderance of justification in the interest of safety for the WSC to prohibit the SIG P320 and its M17 & M18 variants from use on the range by WSC members.
Recommendation –
It is in the interest of safety that the WSC prohibit the SIG P320 and its variants from possession or use on the range by WSC members when under WSC control. Further that the WSC basically mirror the policy statement of the Gunsite Academy as follows –
The Williams Sportsman’s Club has always placed firearms safety as paramount.
Currently, there are significant questions being asked in the shooting sports community about the operation of the Sig P-320 pistol.
The WSC position, effective immediately, is that until these questions have been answered to our satisfaction, the WSC will no longer allow the Sig P-320 pistol and its M17 & M18 variants to be used or possessed by WSC members on the range when under WSC control.
Action –
This item is on the WSC August 13th Board meeting for consideration and possible action.
As always each individual WSC member is solely responsible to follow established range safety regulations, for their own actions, their firearms, and the ammunition they shoot.
FBI Forensic Evaluation Report on Sig Sauer P320 http://www.wearethemighty.com/tactical/the-fbi-evaluation-of-the-sig-sauer-p320/
On March 7, 2025, Sig Sauer, Inc. released a statement affirming that there is no evidence, data, or empirical testing to show that its P320 handgun can discharge without a trigger pull.
But on August 30, 2024, little more than six months before Sig Sauer made that statement, the FBI’s Ballistic Research Facility – the agency’s sole research, development, testing and evaluation facility for weapons, ammunition, armor, and other law enforcement items – published an evaluation of a Sig Sauer M18 (a version of the P320) documenting otherwise.
If Sig Sauer chose to participate in the evaluation, they might have been aware of its findings before releasing their statement, but more on that later.
YouTuber Protraband obtained the BRF evaluation following a FOIA request to the Michigan State Police. Although Protraband redacted the agency’s actual name in his video on the findings in the evaluation, professional shooter Ben Stoeger published a less redacted version of the report on his Instagram account.
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” (great quality control), 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. Still in the holster, the pistol was removed from the (thankfully, uninjured) officer and placed in an evidence bag.
On August 2, 2024, the department requested that the FBI’s Ballistic Research Facility conduct an evaluation of the M18, which began five days later. Although requested by the Michigan State Police, Sig Sauer declined to participate.
Most pilots aren’t aeronautical engineers, most drivers aren’t automotive engineers, and most shooters aren’t firearm engineers. So, I’ll do my best to summarize BRF’s evaluation and findings.
An unnamed executive vice president for Alien Gear participated in the initial evaluation, assessing the holster and confirming that it was undamaged and in normal working order. Once that was set, a BRF staff member then tested the holster. The FBI evaluation says the BRF member was able to force his finger into the holster and reach the trigger, but he experienced “notable discomfort” and “deflection of the skin.”
With FBI funding, the Ballistic Research Facility conducted a battery of scientific analyses on the M18 itself, including X-ray images, coordinate scans, and isolated tests on its firing mechanism. The lab found that the striker safety lock spring was not fully seated and only captured at the top of the striker housing. The sear experienced uneven wear, and the primary and secondary sear notch edges showed signs of wear. Additionally, the bottom of the striker pin hook had a “ledge” instead of being flat.
Using a digital microscope, BRF confirmed that the primary and secondary sear notch edges exhibited wear, the face edges of each notch appeared chipped, and the primary sear ramp had a manufacturing artifact.
That was very technical, so here’s where all of that analysis led: To mimic what a pistol goes through when being carried by an officer who might run, jump, climb, fight, draw the pistol, or just lean against a wall or vehicle, BRF pressed together and pulled apart the M18 at the slide and frame.
Afterward, pressure was applied to the frame, and the sear was manually released from the primary notch, testing the effectiveness of the secondary sear notch to prevent the pistol from firing. The test was performed with the M18 in the holster.
Of the 50 iterations conducted during the FBI evaluation, BRF found the M18 fired a primed case nine times. But this was a used handgun with over 1,000 rounds through it (the Modular Handgun System – of which the M18 is part – requires a service life of 25,000 rounds, but try not to think about that). So the Michigan State Police provided a brand-new, unfired M18 to BRF. In the new M18, the primed case fired on the second attempt.
That was still a lot of technical talk, so here’s the bottom line. BRF admits that they could not develop a reliable test (at the time of publication) to test the effectiveness of the secondary sear notch. However, their testing indicates that movements representing those common to law enforcement officers (and, arguably, military members) have the potential to render the M18’s striker safety lock inoperable and ineffective in preventing the striker from impacting a chambered round if complete sear engagement is lost.
Since movement and friction (common occurrences in the line of duty) can disable the striker safety lock, BRF believes that the potential risk merits further exploration.
Luckily for FBI agents, the bureau issues Glock pistols. The Coast Guard, under the Department of Homeland Security, also evaded the DoD’s Sig contract and uses Glocks. However, Immigration and Customs Enforcement, also under DHS, got its own Sig contract – until now.
MILITARY NEWS
SIG P320 engineering review recommended in Marine Corps report Sig Sauer denies the possibility of reported uncommanded discharges. By Miguel Ortiz Apr 29, 2025
On January 19, 2017, the U.S. Army announced SIG Sauer’s P320 variant as the winner of the Modular Handgun System trials. The Army adopted the full-size and compact variants as the M17 and M18, respectively. In 2019, the Marine Corps ordered the M18 and began equipping
Marines across the fleet with the new pistol. On February 14, 2023, an incident occurred aboard Camp Foster, Okinawa, involving a Marine-issued M18.
New Hampshire Public Radio obtained the investigation report, released on April 4, 2023, through a Freedom of Information Act request. The report notes that Person 1 (P1) was issued an M18 with two 17-round magazines; one magazine was inserted into the pistol, a round was chambered, the safety was engaged, and the M18 was holstered with the cover rotated over it. These actions were witnessed by Person 3 (P3). Along with Person 2 (P2), P1 and P3 proceeded to Gate 1 for guard duty.
For nearly five hours, P1 and P2 rotated standing at the ID checkpoint until 10:00 a.m., when P1’s M18 discharged while standing at the checkpoint.
P2’s statement notes that P2 was in the guard shack and heard a loud noise. Upon exiting, P2 found P1 shaking and nervous. P2 asked what happened, and P1 responded that the M18 discharged. After verifying that P1 was okay, P2 visually checked with P1 that the M18 was in safe mode and called to report the incident. P1’s holster was damaged when the M18 discharged.
The Marine Corps report noted that P1 completed classroom training and hands-on training for the M18 at Camp Hansen, Okinawa, on November 8, 2021, with the most recent training on August 30, 2022. Furthermore, the maintenance record of the M18 showed that it passed inspection and was deemed serviceable on November 22, 2022. A subsequent inspection after the discharge incident also found the pistol to be in serviceable condition.
At the time of the incident, P1 had 7 years and 11 months as a Japanese Security Guard, while P2 and P3 had 20 years and 13 years and 2 months of experience, respectively. The report also notes that P1 was not taking medication, did not drink alcohol, and was well-rested the night before the incident.
After reviewing the security camera video footage, the Marine Corps investigator concluded that P1 did not mishandle the M18 prior to discharge. From the evidence and statements of the people involved, the investigation concludes that the M18 was on safe and secure in the holster. As a result, the investigator recommended conducting an engineering review of the M18.
On March 7, 2025, SIG Sauer released a statement affirming, “The P320 CANNOT, under any circumstances, discharge without a trigger pull – that is a fact. The allegations against the P320 are nothing more than individuals seeking to profit or avoid personal responsibility.”
Additionally, the Marine Corps investigator recommended that the policy on weapon condition status be reviewed. Rather than having the M18 in condition 1 with a round chambered and the safety on, the investigator recommends that condition 3, with a magazine inserted but no round chambered, be employed during lower Force Protection Condition levels.
This reduced level of readiness would be in contrast to the Marine Corps policy for the M9 and M45A1 pistols, which required them to have a round chambered and safety engaged when carried by Marines and civilian law enforcement and security personnel.
Sig Sauer P320 prohibition
Gunsite Academy has always placed firearms safety as paramount.
Currently, there are significant questions being asked in our community about the operation of the Sig 320 pistol.
After much consideration, we have decided that until these questions have been answered to our satisfaction, Gunsite will no longer allow the sig 320 pistol to be used in classes, effective immediately. If the sig 320 is a government-issued duty pistol for military or law enforcement students, we will allow – but discourage the use of – the sig P320 for that student. Other Sig platforms continue to be welcome in classes.
Sig is a well-known leader in our industry and we are confident they are working diligently to investigate the possible underlying problem. Once the issue is resolved, we will reconsider our prohibition.
Dear Pima Pistol Club Members,
We are writing to inform you that, due to recent events, the SIG Sauer P320 pistol (all variants) will be temporarily banned from use on Pima Pistol Club property. The Board of Directors will be discussing this matter in greater detail at our upcoming monthly board meeting, which will be held on Tuesday, August 12th at 6:00 PM. All members are encouraged to attend and participate in the discussion.
We appreciate your understanding and cooperation as we work to ensure the continued safety of our shooting community. If you have any questions or concerns, please feel free to reach out.
Chris Kilijanczyk
Range Manager
Pima Pistol Club
rangemanager@pimapistolclub.com
520-825-4440
Williams Sportsman's Club 