SIG Sauer California Compliant P365 9mm: Full Review

The pause to microstamping restrictions in California let manufacturers introduce some up-to-date handgun models to the Golden State. SIG was no slouch, bringing the P365 to the table as well. Here's a full review.

March 31, 2025 By Guns & Ammo Staff

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Anyone that has been in a gunfight will agree, you can’t have too much ammo. When SIG Sauer introduced the P365 in Guns & Ammo’s May 2018 issue, it invigorated the micro-compact pistol market. Its thin, 1-inch profile, 5.8-inch overall length and 3.1-inch barrel — combined with either a 10- or 12-plus-one capacity magazine — was what the concealed-carry community had clamored for. In the December issue, it became the 2018 G&A Handgun of the Year. The P365 overtook sales of the single-stack, eight-plus-one capacity pistols and double-stack compacts that were the norm. The P365 was such a hit, other firearm companies quickly introduced a similarly inspired model. Though pistols with similar dimensions and capacities had existed prior to the P365, the timing of its launch and market impact gave birth to the “micro-compact” category.

Microstamping

California’s restrictive gun laws prevented the P365 from reaching many hands. In 2013, the microstamping provision of California’s Unsafe Handgun Act (UHA) became active, creating a de facto ban on new semiautomatic handguns. Military and law enforcement officers were exempt. No semiautomatic handgun could be sold in California unless the firing pin was etched with an array of numbers that identified the firearm’s serial number, make and model. When fired, the intent was that these numbers would be stamped on the cartridge’s primer. Of course, handguns were already serialized. The technology used to etch the characters on the firing pin was questionable and prohibitively expensive. Even the most perfect implementation of an imprinted firing pin could be destroyed with a scuff or normal use. Firearm manufacturers never implemented the technology.

gaad-250200-ph2-sig-sauer-p365-california-9mm-02-1200x800 — Per California regulations, a loaded chamber indicator had to be developed for the P365, as well as a marking that described its function. The warning is laser-engraved onto the optic coverplate. (Photo by Alfredo Rico)

The provision was challenged in the Boland v. Bonta case. It was ruled “unconstitutional,” and regarded as commercially unviable to implement on a mass scale. In 2023, the microstamping requirement was suspended, which opened the doors and welcomed new pistol models to enter California. The ruling was immediately appealed and may be reinstated in January 2028 if the California Department of Justice determines microstamping is viable. Other states, including New York and New Jersey have adopted microstamping laws, as well.

Added Hurdles

Suspending the microstamping component was one of the UHA hurdles for new semiautomatic handguns entering California. Two additional safety features were required, but were not as impossible for manufacturers to meet. One is a magazine disconnect, the other a loaded chamber indicator (LCI). The former prevents the handgun from firing unless a magazine is seated into the grip. No magazine, no “pew.” The LCI is a lever that protrudes above the slide when a round is in the chamber. The words “LOADED WHEN UP” must also be printed in view on the slide. The P365 California model has these words on the slide’s optic-plate cover. You should always assume a firearm is loaded, but the physical and visual indicator of a firearm’s status is a feature that many will accept.

gaad-250200-ph2-sig-sauer-p365-california-9mm-03-1200x800 — While most SIG Sauer P365 extended basepads also offer additional magazine capacity, the magazines supplied with the P365 California are restricted to 10 rounds. (Photo by Alfredo Rico)

Still Growing

The P365 line has expanded considerably since its introduction. Its modularity allows it to be configured with various combinations of grip modules and barrel lengths. As of this report, there are 22 models offered, including the P365 with the 3.1-inch barrel and 12-round magazine to the P365-Fuse, which has a 4.3-inch barrel and 21-round capacity. SIG Sauer released two California-compliant P365 models in 2024, the P365 and the P365-XMacro Comp. Guns & Ammo received the P365 for evaluation, which is like the 2018 original except for the addition of an optic cut.

California-compliant P365 models are chambered in 9mm. The .380 version is not available yet. They include a manual safety lever — standard — an optic-ready slide, and two 10-round magazines. (Ten rounds are the legal maximum magazine capacity in California.) One magazine is flush fit, and the other is extended with a shelf for the pinky finger. The optic footprint is patterned for the RMSc.

The stack-and-a-half magazine is the foundational architecture for the P365. SIG Sauer submitted three patents for the magazine concerning the follower, magazine body and spring. The result was svelte 1.1-inch grip width. The pistol’s carbon steel barrel measured 3.1 inches, keeping its overall length to 5.8 inches and height to 4.3 inches.

Mounted to the slide are SIG Sauer XRAY3 day/night sights. The rear sight is a serrated, U-notch with two tritium dots. The front post has a tritium center dot surrounded by a highly visible fluorescent polymer ring.

gaad-250200-ph2-sig-sauer-p365-california-9mm-04-1200x800 — SIG Sauer XRAY3 day/night sights are dovetailed into the slide. The front features a green ring around the tritium vial, and the rear sight is serrated to reduce glare with two tritium laps flanking the notch. (Photo by Alfredo Rico)

Slide serrations are at the front and rear of the stainless-steel slide. To manage reliability with so many types of 9mm rounds with a short barrel, the P365 uses a compound recoil spring assembly. There are two progressive springs, that are not too stiff for most people to rack the slide.

The polymer grip module is ergonomically shaped, providing a firm and comfortable grip. The deep triggerguard undercut lowers the barrel bore for better recoil control. The front strap has two finger grooves, one is slightly shallower than the other. The grip area above the magazine release is concave, providing a shallow shelf for the support hand’s thumb. Adding to its control is the mild, sandpaper-like texture that dominates the lower the grip. Hand placement is natural, and the magazine release is reversible.

The Structure

For those who like customizing firearms, the modularity of the fire control unit (FCU) supports it. The FCU includes the chassis that secures the mechanical components including the trigger, takedown lever and manual safety. Typically, these components are arranged and pinned inside the lower grip. The FCU is made from stainless steel and is the serialized firearm. Once removed, it can be installed in another compatible grip module. The FCU is locked into the grip module by a single receiver pin. The grip module has no working parts aside from the magazine release button.

The popularity of the P365 series has invited a host of aftermarket accessories. The grip module, slide and barrel are even available as custom upgrades from SIG Sauer and other vendors. The grip module is an especially popular update. SIG Sauer offers three color choices for the P365 with manual safety, including several made from billet aluminum by Juggernaut Tactical. A word of caution: Ensure that the P365 FCU is compatible with the aftermarket grip module you choose, or they will not be an easy drop-in. Some grip modules require gunsmithing.

From the Holster

Two months were spent with the P365. G&A contributor and photographer Alfredo Rico carried it as part of his everday carry (EDC) in a N8 Tactical Xecutive holster. and found its weight and shape easy to conceal. He also wore it with a Streamlight TLR-7 HL-X Sub ($266, streamlight.com) light. The light boasts 1,000 lumens of brightness and is USB rechargeable with a front-loading battery. When ordering the N8 Tactical Xecutive holster, there was an option for this light.

The grip texture was a little rough but it did not chafe. The depth of the beavertail and trigger undercut allows the pistol to ride low in a grip for excellent recoil control. When the pistol was drawn, the XRAY3 sights appear on target without a lot of searching. Featuring tritium for night sight capability, they were easy to see and align in low light.

For accuracy testing, a Riton 3 Tactix MPRD 3 was mounted. There are three reticles built in: 3-MOA dot, 30-MOA circle and a combination. The 3-MOA dot permitted enough refinement for group shooting at 25 yards.

gaad-250200-ph2-sig-sauer-p365-california-9mm-06-1200x800 — The Fire Control Unit (FCU) is removable, and is the only serialized component on the California-compliant P365. The FCU is supported by an extensive aftermarket.(Photo by Alfredo Rico)

Shooting the P365 produced better results than in 2018, even. The pistol recoil was soft and sights came back on target after each shot. The trigger press measured 6 pounds, 5 ounces. It’s takeup was smooth, but there was a heavy wall before it fired. Regardless, the pistol was accurate at 25 yards. Shots landed within a hand’s width on the chest at that distance. Most groups had near a 2 1/2-inch spread.

When reloading, the magazine release felt a little too low and distant for small- and medium-hand size users. Pressing it required rotating their grip slightly. However, there were no issues driving the magazine into the grip. The layout and size of the takedown lever, slide catch and manual safety were perfect. They protrude enough from the grip module to easily access them. The manual safety wasn’t troublesome to work with, either. With a little time at the range, engaging and disengaging it was an easy habit to pick up. We also liked the forward placement of the slide catch next to the takedown lever. On some small pistols, it is located farther rearward where the shooting hand’s thumb may unintentionally press it, sometimes preventing the slide from locking back on the last round.

To explore the modularity of the FCU, we also tested it into a Sharps Bros. grip module. They have a specific model for the California-compliant P365 with the manual safety. The appeal of it is that it is made of aluminum, has a 11/4-inch-wide grip and includes ambidextrous “gas pedals.” The gas pedal served as a great indexing point for the thumb. Using Hornady’s Critical Defense to group with, Sharp Bros. grip module returned our best groups. The only downside was that the grip module did not fit the N8 Tactical test holster due to the width of the thumb supports. However, the Xecutive holster with the light option accepted the grip — but not with the light installed.

gaad-250200-ph2-sig-sauer-p365-california-9mm-07-1200x800 — (Photo by Alfredo Rico)

Final Shot

When G&A first spent time testing the micro-compact P365, we thought we would miss the larger pistols more. Alas, we do not. In 2018, the award-winning P365 was the new standard for comparison, the concealed-carry pistol to beat. The extended magazine fills most people’s hands nicely, and the stack-and-a-half magazine design managed to reduce bulk, while improving ergonomics and comfort. Carrying a larger frame for capacity’s sake is not an advantage to Californians due the state’s 10-round maximum capacity law. However, the P365 is a worthy option. To that end, aftermarket support also makes the P365 an attractive model. Like any product that makes a paradigm shift, the P365 is still the micro-pistol all others are compared to.