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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.
The actual Sig Sauer M18 evaluated by the FBI’s Ballistic Research Facility (@benstoeger via Instagram)
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 M18 was properly seated in the holster with all levels of retention in place (@benstoeger via Instagram)
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.”
The pistol fired and the trigger reset, but the fired case did not eject (@benstoeger via Instagram)
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.
Note the lack of a trigger pull (@benstoeger via Instagram)
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.
On July 9, a memo from ICE Deputy Director Madison Sheahan banned the Sig P320 for carry by ICE agents. Instead, ICE will purchase Glock 19s for its agents to use going forward. Between the FBI evaluation and this move by ICE, the American taxpayer would be justified in wondering who in the Army chose Sig Sauer over Glock for the $580 million Modular Handgun System contract. After all, the lowest bidder still has to deliver a product that meets the standard.
