Even though I’m in the business of writing about firearms, I have a dirty little secret—my embarrassing list of popular guns in circulation that I’ve never shot before. Among these are the Browning Hi Power, the FN SCAR, the Ruger 10/22, the Mossberg 590, the Ruger SP101, the Savage 110, and, up until very recently, the SIG-Sauer P365.
(And worry not, because I am waiting on a Savage 110 Magpul Scout to review in the coming weeks).
As far as the Ruger 10/22 is concerned, I don’t really have an answer for that one. I always preferred bolt-action .22 LR rifles, I guess…
But damn, it was about time I tried shooting a SIG Sauer P365. I’m penning this only a few days after submitting my SIG Sauer P365 FUSE review manuscript to another publication. But prior to conducting that review, I had no practical experience with SIG Sauer’s popular micro-compact models.
I’m not completely oblivious to the SIG P365. These pistols constitute some of SIG Sauer’s best-sellers amongst guns sold today. P365s can be found in nearly any establishment that sells firearms, be they mom-and-pop shops or big-box operations. Their slimmer profiles and micro-compact frames lend themselves quite well to carrying convenience, and there’s no doubt that their practicality and form factor also.
The original version of the SIG Sauer P365 was launched in January 2018. It turned many heads because it somehow managed to squeeze so many 9mm cartridges into its micro-compact frame. From that point forward, these little guns took off, and it wasn’t long before nearly every concealment holster maker began offering fits for them.
The P365 Blueprint
Two key elements in its initial success lie in the P365’s “stack-and-a-half” magazine designs that allow for a great size to capacity ratio. Likewise, it the fact that P365s are built around an FCU (fire control unit). The fire control unit is a concept borrowed from the original SIG-Sauer P250.
Its gist is that the trigger mechanism is contained in a serialized (and regulated) sub-assembly, which is independent of the actual grip or frame. Both of these elements meant that it wasn’t difficult for SIG-Sauer to build off the P365’s core design without having to reinvent the wheel. In a similar vein, the FCU is the reason why the SIG P320 also has an entire laundry list of sub-variants.
Besides the original 2018 P365 model, other notable P365 product launches include the slightly larger P365 XL that followed in June of 2019. During the autumn of 2022, three years later, the even bigger P365 X-Macro models made their way into gun shop display cases. The X-Macro guns were the first to sport 17-round standard-capacity magazines, and I distinctly remember my bewilderment. “17 rounds in a frame of that size?”
Finally, last summer, SIG Sauer followed up after the XL and Macro models by introducing P365 FUSE—the inspiration behind this article.
Full-Size FUSE

The SIG-Sauer P365 FUSE is currently the largest variant in the SIG-Sauer P365 product line. Like the SIG P365 X-Macro models, the P365 FUSE includes a standard capacity 17-round magazine. Unlike its X-Macro siblings, the FUSE has a longer 4.3-inch barrel. It does share the same frame otherwise, and all FUSE slides are optics-ready.
The P365 FUSE checks off virtually most of the specs found on contemporary duty-size polymer-frame striker-fired 9mm pistols. However, thanks to that stack-and-a-half magazine scheme and its FCU, the grip module retains the original thinner width of the standard SIG P365. This means that the FUSE doesn’t feel like a typical double-stack striker gun at all.
The thing about the P365 FUSE is that its most important details overlap with those of full-size 9mm duty handguns—that higher capacity and barrel length longer than four inches (a benefit when it comes to muzzle velocity development). And being brand new to the P365 family, I think that’s what makes the FUSE in particular so interesting.
The combination of its size, features, and specifications could make it a do-it-all gun for a general-purpose use case. It is thinner and thus easier to carry, but it does so without giving up any firepower or handling ability.
In my formal review, I noted that the grip is long enough to accommodate the three fingers of most adults’ firing hands comfortably. Such an attribute allows the gun to be extremely controllable despite its lighter weight. Yes, felt-recoil is consequently more noticeable, but not to any detrimental extent. In the review, I also touch on the fact that a smaller overall circumference of the grip makes it easier to grip harder and thus control better, too.
Can The P365 FUSE It Do It All?
I’m only 300 rounds into this gun, which is a pithy sum of ammo, all things considered. So, it would be physically impossible to write a long-term report on my experiences. A break-in was practically mandatory because the slide was extremely stiff when racking. Most handguns, even modern ones, always “feel” better after shooting at least those first 200 or so rounds through them. Specifically for the P365 FUSE, I felt that the break-in period was actually mandatory.
During the first few mags, I had several instances of the pistol failing to fully go into battery with factory 124 NATO loads. I think I’m in the clear after the first 200 rounds, but I wouldn’t mind shooting the pistol some more to be sure, given my lack of hands-on familiarity with P365 models.
After shooting the gun from the rest for the original review, its apparent mechanical accuracy really impressed me. The P365 FUSE sports a carbon-steel barrel rifled with a ubiquitous barrel twist of 1:10. Hornady’s 115-grain Critical Defense XTP based load printed tightly at 15-yards. However, I’m even more excited about its potential with 147-grain bullets.
So far I’ve only tried HOP Munitions’ 147-grain Poly RN match loads which have an advertised muzzle velocity of 900 fps and are designed to make minor power-factor. 20 of these averaged out to 904 FPS and a power-factor of 132. Their gentler recoil impulse also made shooting this load very comfortable; I wouldn’t have any qualms about shooting this gun in USPSA Carry Optics.
The FUSE’s Stock Trigger

Unfortunately, some of its prime accuracy can be somewhat offset by its stock trigger. Though manageable, it requires a lot of practice and deliberate trigger management. If one isn’t careful when breaking the shot with this trigger, one can end up printing fliers and throwing shots.
Personally, I don’t think it’s the end of the world. As a striker-fired trigger without a bladed safety, I find that my P365 FUSE’s actual trigger-pull weight and required travel distance more than make up for that. This is a defensive carry pistol and not a 50-yard Camp Perry gun after all.
To best answer the question about whether this skinny gun could “really do it all”, I’d have to keep shooting and training with the pistol to see how it performs over the long-term. I am not sweating the pre-break-in stoppages I experienced, but I want to ensure they were just that and nothing more.
I’m also interested in seeing if and how the feeling of the trigger pull changes once the gun gets to its first 1000 rounds.
The Takeaway
In the end, I also recognize that this handgun won’t be everyone’s cup of tea either.
First, it still has an overall length of more than 7 inches, which can make concealment tricky for some. Its thinness is irrelevant in this regard.
Two, I can imagine that a certain pool of sophisticated handgun shooters will want nothing to do with the pistol due to its trigger pull. Personally, I don’t mind the trade-off, considering all of the benefits the P365 FUSE posits. Likewise, as with all other P365s, the P365 FUSE also lacks fully ambidextrous controls. There’s only one slide-release lever on the left side of the pistol meant for right-handed shooters.
It can be a potential deal-breaker for some. Again, it’s a trade-off. As a left-handed shooter, I’m already used to adapting to a right-handed firearms world. Due to its thinness, the P365 FUSE slide only works with RMSc/Holosun-K optics footprints, and similarly, its accessory rail accepts smaller TLR-7-sized weapon lights.
The SIG P365 FUSE Isn’t the First of Its Kind
Finally, it’s also worth pointing out that the P365 FUSE isn’t actually the first pistol of its kind to hit the market. That distinction arguably belongs to the Glock 48, which is slightly smaller than the FUSE, but only marginally. After all, what is a Glock 48 but a skinny Glock 19?
One of the first things I did when I brought the P365 FUSE home was to put it beside the Glock 48 and size it up. Not surprisingly, they share a similar footprint, with the FUSE being slightly larger and longer.
The FUSE also isn’t the only contender in the game, as different gunmakers also offer thinner-but-bigger models centered around practical daily carry. But tying it back to its original P365 parent, seeing where the modularity of SIG-Sauer’s P365 FCU and stack-and-a-half magazine design attributes are taking modern carry pistols is getting very interesting.
This counts not only for the SIG-Sauer P365 FUSE but also its competitors.
