Upon release, the SIG Sauer P365 pistol was and still is one of the most influential handguns of the last 10 years. SIG and their P365 were initially responsible for launching what has to be a revolution in terms of micro-compact pistols. This newish category of handguns is always attempting to strike a balance between the concealability of pocket pistols like the original Smith & Wesson Shield, and the shooting characteristics of larger compact pistols like the Glock 19. However, the new SIG Sauer P365 Fuse is doing almost the exact opposite. While the Fuse variant of the P365 maintains the slim profile of its namesake, the Fuse is much larger than any variant of the P365 thus far - about the same footprint as a P320 because of the Fuse’s included 21-round mag, 4.3” slide length. Lena Mickuleck herself likes to call this type of handgun a “skinny full-size.”

 

p365 fuse

 

Why A Skinny Full-Size?

You might be asking yourself why you’d even want to configure a handgun this way. The main benefit of having a slimmer gun is that it makes it a lot easier to conceal. It prints less, is less bulky, and typically carries more rounds than pocket pistols do. The P365 Fuse has a much larger Macro-sized grip that is then outfitted with a removable magwell to aid in reloads. Actually, there are a lot of little improvements that the Fuse has so I’ll just list them here:

 

SIG Sauer P365-FUSE Key Features:

  • Optic-Ready Slide: The stainless steel slide with a compact footprint features aggressive serrations and a durable Nitron finish, providing a sleek look and enhanced functionality.
  • High-Performance Barrel: The 4.3-inch carbon steel barrel with a DLC finish ensures longevity and precision shooting.
  • Versatile Magazine Options: Comes with two 21-round and one 17-round steel magazine, giving you the flexibility to choose the best capacity for your needs.
  • Advanced Grip Module: The polymer LXG grip module boasts a laser-engraved texture, a 1913 accessory rail, and a removable magwell, along with interchangeable small, medium, and large backstraps for a customized fit.
  • Enhanced Trigger and Sights: Features a nickel-plated flat-faced trigger for a smooth pull and a fiber optic front sight with a black serrated rear sight for quick and accurate target acquisition.

 

The takeaway here for me is that this pistol can do pretty much anything. With the removable grip magwell, flush-fit 17-round magazine, and interchangeable backstraps, you can optimize the gun for concealed carry for most days, and then slap the magwell back on for competition or range days. The pistol also comes equipped with a dust cover rail, so mounting lights - especially modern ocmpact lights can extend the pistols usefulness even further. With an asking price of around $700, what you’re essentially buying is a very refined, large-format version of the P365 pistol. If you’re into tinkering or just need one gun to do it all, I’d say it’s for sure worth picking up.

 

p365 fuse with optic

Accuracy and Performance

If there’s one thing the P365 Fuse delivers in spades, it’s accuracy. The longer 4.3-inch slide and barrel don’t just improve sight radius—they also help with velocity, which is great if you’re running +P loads for extra stopping power. Combine that with the upgraded fiber optic front sight and black serrated rear sight, and you’ve got a pistol that’s easy to shoot with confidence, even at longer distances. Whether you’re putting rounds downrange for fun or dialing in precise shots in a competitive match, the Fuse performs like a champ. It’s the kind of accuracy you’ll notice right away, even if you’re upgrading from the standard P365.

Real-World Versatility of the Fuse

The Sig Sauer P365 Fuse is a rare breed of pistol that truly does it all. With its slim profile and removable magwell, you can set it up for concealed carry one day and transform it into a competition-ready powerhouse the next. The included 21-round and 17-round magazines mean you’ve got firepower to spare, whether you’re heading to the range or prepping for home defense. And because the Fuse stays true to the P365’s modular roots, you’ve got endless customization options to make it your own. It’s not just a skinny full-size—it’s your all-in-one handgun solution.

New Gun, Old Problems - Upgrades

A lot of people take issue with the P365 platform for one reason or another. I personally love the P365 but I do think that one of its weakest points is its trigger and it’s something that’s been improved but not quite fixed for me with the P365 Fuse. Tyrant’s own P365 Intellifire trigger takes out a lot of that classic P365 slop in the pre-travel and also adds a bit of extra safety with the addition of a blade-style trigger safety.

Since the frame of the Fuse is in the Macro style, this means that the 17-round mags that the Fuse ships with can also be extended with Tyrant’s P365 XMACRO magazine extension to push them from 17 rounds up to 20 rounds - nearly as much as the new 21-round OEM mags that SIG is shipping with the Fuse. While this isn’t a necessity for me, I still think it’d be great to upgrade my old P365 XMACRO 17-round mags to work with the new Fuse in a competition capacity.

If we’re going to go down the competition rabbit hole with the Fuse (which is what I think we’ll start seeing a lot of people in the carry optics division do), another smart upgrade for it would be extended controls like an extended takedown lever to be used as a lower-profile gas pedal, extended slide catch lever for better reload flexibility, and of course an extended magazine release. I have one of the Tyrant P365 Magazine releases on a Mischief Machine OMEGA lower and it’s by far the best upgrade I’ve made to the gun after adopting the all-aluminum frame.

 

p365 fuse

Worth The Buy?

The P365 Fuse is probably going to once again change the landscape of the handgun world. While the idea of a slimmer full-size gun might fly in the face of everything we’ve come to expect from the historically extremely concealable P365 series, the new Fuse does present a decent case as being the next “Glock 19” of the firearm world. The Fuse comes pre-equipped with everything you need but also has a lot of room for people to adapt it to their exact needs and tastes since it’s still living in the world of the P365, its FCU, and all of its compatible aftermarket parts.

I have guns that I have been shooting, and carrying for years in more or less the same configuration. However, I occasionally like to have “project guns” that I mess around with and typically turn into range toys for fun. I don’t think I see a P365 Fuse in my carry rotation, partially because it’s on the larger side of what I’m comfortable carrying for most of the year. I would however be really interested in turning one into a USPSA Carry Optics or IDPA gun specifically because it is so easily customizable, and still solidly fits within the spirit of both those disciplines.

Of course, we’d like to hear what you think of the new P365 Fuse! What would you change or upgrade about SIG’s new “skinny micro compact?” Let us know in the comments, we’d love to hear from you.

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FAQs

Is the Sig P365 Fuse worth it?

Yes, the P365 Fuse is worth it if you're looking for a versatile, slim "full-size" pistol that balances concealability with competition-ready features. Its customizable grip, extended mags, and optic-ready slide make it a solid investment for those who want a do-it-all firearm.

Is the Sig P365 Fuse reliable?

Yes, the P365 Fuse is reliable, carrying over the trusted dependability of the P365 platform while adding features like improved ergonomics and high-capacity magazines.

What is the difference between the P365 and P365 Fuse?

The P365 Fuse features a longer 4.3-inch slide, higher magazine capacity (up to 21 rounds), and a larger Macro-style grip with interchangeable backstraps and a removable magwell. It’s essentially a slimmed-down full-size pistol, offering more versatility than the original P365.