Reviews This Gun Flux: SIG Sauer P365-FLUX [REVIEW] David Lane January 16, 2026 Join the Conversation At RECOIL, we review every product fairly and without bias. Making a purchase through one of our links may earn us a small commission, and helps support independent gun reviews. Read our affiliate policy. Find out more about how we test products. Images by Patrick McCarthy / Match Grade Media What started in 2018 as the SIG SUAER P365, a micro-compact pistol sporting an industry-shocking 10-round magazine, has become something totally different 7 years later. Since that original release, SIG has sent from their doors a dozen different sizes and flavors of the P365 going from the micro-compact P365 release to the P365X, XL, MACRO. MACRO-Comp, all the way to the nearly-full-suze FUSE. Now, far larger than a full-size pistol, we have the P365-FLUX, a PDW with brace, muzzle shroud, 6” barrel, and optic. What started as 10+1 is now 25+1+25 with the extra magazine slot forward of the grip. The weirdest part? The P365-FLUX still fits in your pants and is entirely concealable. P365-FLUX SPECS CALIBER: 9mm Luger PISTOLSIZE: Compact PDW MAGS INCLUDED: (2) 17rd / (1) 25rd Steel Mags SIGHTS: XRAY3 Day/Night Sights OPTIC READY: Yes SIGHT RADIUS: 5.6 in SLIDEFINISH: Nitron® SLIDE MATERIAL: Stainless Steel ELECTRO-OPTIC INSTALLED: Yes TRIGGER ACTION: Striker TRIGGER TYPE: Flat Faced MANUAL SAFETY: Yes FRAME MATERIAL: Stainless Steel GRIP MODULE: FLUX P365 Chassis GRIP MATERIAL: Standard Polymer GRIP COLOR: Black ACCESSORY RAIL: 1913 Picatinny Rail FCU MATERIAL: Stainless Steel BARRELLENGTH: 6 in [152.4 mm] THREADED BARREL: No BARREL MATERIAL: Carbon Steel OVERALL LENGTH: 19.1 in [486 mm] OVERALL WIDTH: 1.34 in Deployed / 1.52 in Folded [34 mm / 39 mm] HEIGHT: 7.75 in WEIGHT: 49.2 oz [1395 g] FLUX DEFENSE AND SIG SAUER Credit for the P365-FLUX doesn’t have much to do with SIG Sauer and is almost entirely due to Flux Defense, the inventors of the P320 Raider X and Raider 365 chassis. First offered in Aluminum, the Raider 365 was a DIY upgrade for a P365 giving you the option of turning your boring EDC micro-compact into a fancy PDW with a lot more sex appeal. SIG Sauer isn’t known for partnering with outside brands, but it seems Flux was too good to ignore because not long after the Raider 365 hit the market, SIG announced the P365-FLUX. This package, direct from SIG, took the DIY chassis and turned it into a complete factory product straight from SIG. We’ve covered the standalone Flux Defense Raider 365 chassis before, but it’s worth talking about again. Because the SIG P365 uses a serialized Fire Control Unit as the true “firearm” part, it has the ability to change grip modules at will. The Flux chassis is, effectively, a new grip module that the P365 FCU drops into. The normal chassis then pairs with a normal P365 slide and barrel assembly, and you’re good to go. The version direct from SIG comes as a completed package with the FCU installed in a Flux Ultralight chassis, P365 slide, special 6” barrel, and Romeo X Enclosed redot mounted on top. The Flux chassis major features are the same from SIG as the DIY version from Flux Defense. Fitted with a pistol brace that folds down flat, it’s easy to release with just a press forward on a right-side-mounted button conveniently near your index finger. Even drawing from a holster, this is easy to press and deploy in a smooth draw stroke. The brace is spring-loaded and is assisted in opening by a piece of bungee cord. Less authoritative than it could be, but the brace deploys quickly enough. Forward of the pistol grip is a magazine attachment point for storing a spare magazine. Behind this extra mag well is a magazine release that will drop the forward spare mag with a soft press, or drop both the forward magazine and the primary magazine with a harder press of the button. This nifty little feature is patented by Flux. 6” of barrel ends up sitting out from the slide, but this extra barrel is hidden and protected by a shroud. The shroud allows for a good C-clamp grip if you so choose, but I’m not convinced that’s really the best option here. 1913 Picatinny railing is set under the barrel shroud for mounting lights. Something full-size like a Streamlight TLR-7 or SureFire X300 won’t fit due to the pistol brace needing to fold flush with the end of the muzzle, but slightly smaller lights like the Streamlight TLR-7 or TLR-7 SUB fit perfectly. PCC, PDW, SBR, OH MY In the firearms world, names tend to have a lot of different meanings, and sometimes no meaning at all. While the final definitions and differences between a Personal Defense Weapon and Pistol Caliber Carbine are fuzzy at best, something that is legally defined is Short Barreled Rifle. Since the P365-FLUX has a wire thingy that folds out, you might think it’s an SBR. But we live in an age where names are what you make of them, and just like it says right on the side of the chassis, it’s a brace — not a stock. The legalities of brace vs. stock are confusing and ill-defined, but the bottom line is that since this is a “brace,” it’s not a “stock.” And since it’s not a “stock,” it can’t be a short barreled rifle. If you’re new to this and already confused, that’s normal. The deeper you go down this rabbit hole, the worse your symptoms will get. Before you get to the mygrain level, let’s just make it simple and say that the P365-FLUX is produced and sold by SIG SAUER, and their lawyers feel confident that this is a braced pistol and is not subject to the NFA. P365-FLUX ON THE RANGE From the first trigger pull, it’s clear that this isn’t a pistol, and this isn’t a pistol caliber carbine either. PDW is what Flux and SIG both call it, but I’m not even sure it’s that, but it’s close enough. If you focus on the gun, it feels weird. The red dot is really close to your face, the slide is uncomfortably close to your nose, the brace’s frame digs into your cheek, and slaps you in the face when you pull the trigger. The trigger itself feels like a defensive pistol’s trigger and not like a smooth PCC trigger. Your support hand is confused at best because you don’t grip it like a pistol, but you have a shroud over the barrel so you can C-clamp it… But with a light attached, it’s ergonomically compromised, and if you do try to C-clamp the forend, you now have your own hand in your sight picture. Whenever a new firearm comes in for review, the first thing that happens is some dry fire sessions. In dry fire, the P365-FLUX feels wrong in almost every way. But the review doesn’t stop there. The first range session with the P365-FLUX wasn’t to plink around and get to know the gun. Instead, it was a local steel match with stages designed much like USPSA, but with steel targets. This makes for a fast and friendly match that doesn’t require much resetting and zero taping. From the first beep on the first stage, all of those quirks found in dry fire evaporated. Sure, the P365-FLUX still isn’t the most comfortable gun to shoot. But if you let it, it will run like a scalded cat. Everything about shooting the P365-FLUX is different than a normal PCC or a normal pistol, but it runs fast and makes precision hits. Even going up against shooters with real race-gun PCCs like customized MP5s, JP-5s, and MeanArms uppers — my little P365-FLUX didn’t do too bad, pulling 3rd overall at a match dominated by PCCs. That being said, this isn’t a competition gun. You can use it in competition, but that isn’t the main goal. This is a personal defense weapon, and it shines in that role. Small enough with the brace collapsed to be carried concealed, this is a lot of firearm to be packed in such a small format. The brace doesn’t turn this into the perfect PCC, but it does enhance the P365 into something far more controllable and shootable than what a basic P365 gives you. I don’t see myself ever carrying this in the holster for EDC, but for a “Get Home” bag or something of the like, this is a great option. HOLSTERS AND EXTRAS Holsters for the P365-FLUX and the Raider 365 chassis in general are offered from a few sources, but not many. Just recently, Flux Defense released their 2.0 version holster, and it’s proven to be a huge step up from the first design. This second holster works both for in-waistband and outside-waistband carry, concealed or open. With a generous number of mounting points, it’s easy to add whatever hardware the heart desires to make this holster fit whatever is needed. Mine was rigged with a Safariland QLS fork to use on my competition/training belt that sees the most use. The Flux holster is simple, but it works well. No active retention or fancy features, it’s just polymer and screws to make a shell that fits snuggly but doesn’t grip the P365-FLUX too tightly. Also available are two versions of a Flux magwell: Carry and Full-Size. A slightly larger magwell is never a bad thing, and these work as expected. Maybe not a required addition, but it’s nice to have the option available. LOOSE ROUNDS The worst part about the P365-FLUX is the price. While SIG doesn’t publish MSRP anymore, it looks like the MSRP for this is about $1,650. That is a lot. But the Flux Defense chassis on its own is $520 for the Aluminum version and $500 for the Ultralight. A $500 chassis plus a P365 pistol with a special barrel, plus the enclosed Romeo X red dot, and the price tag makes sense. It’s still a lot of money, but it makes sense. And compared to other good PDWs on the market, $1,650 isn’t as harsh as it sounds. Springfield Kuna runs $1,000, B&T TP9 is close to $2,500, a decent MP5 clone is about $1,000. And none of those come with a red dot, and none of them have the same form factor that the P365-FLUX has. After putting a case of ammo through the P365-FLUX and getting to know it, I dig it a lot. It’s not a pistol, it’s not a PCC, but it’s better in most ways than either one. Why you can trust RECOIL Since our founding in 2012, RECOIL remains the premier firearms lifestyle publication for the modern shooting enthusiast. We deliver cutting-edge coverage of guns, gear, accessories and technology. We go beyond basic reviews, providing no B.S. buyer’s guides, hands-on testing and expert analysis on everything from firearms and survival equipment to watches and vehicles. Our reviewers are the backbone of our operation and come from diverse shooting backgrounds: Former law enforcement, military veterans, competitive shooters, seasoned hunters and plain old firearms enthusiasts. Furthermore, we’re not just gun experts, but dedicated journalists who adhere to the strictest standards of our profession. At RECOIL, editorial independence is the foundation of everything we publish and the cornerstone of reader trust. Our editors, writers and content creators make all editorial decisions independently, free from outside influence. That boils down to: advertisers don’t dictate our coverage, the outcomes of our reviews or what we recommend in our buyer’s guides. First and always, our commitment is to our audience—ensuring every review and article is accurate, unbiased, and driven by real-world experience. Whether you’re selecting your next firearm, upgrading your gear, or exploring the latest innovations in the shooting world, RECOIL provides the trusted insights you need to make informed decisions. Learn more about our Editorial Standards and how we review products. NEXT STEP: Download Your Free Target Pack from RECOILFor years, RECOIL magazine has treated its readers to a full-size (sometimes full color!) shooting target tucked into each big issue. Now we've compiled over 50 of our most popular targets into this one digital PDF download. From handgun drills to AR-15 practice, these 50+ targets have you covered. Print off as many as you like (ammo not included). Get your pack of 50 Print-at-Home targets when you subscribe to the RECOIL email newsletter. We'll send you weekly updates on guns, gear, industry news, and special offers from leading manufacturers - your guide to the firearms lifestyle.You want this. Trust Us.
