TFB Review: SIG Sauer P365-FLUX

Overview

The P365-Flux is a new offering from SIG, based on a proven platform. It is a collaboration between SIG and Flux Defense, maker of the Flux Raider chassis system. The chassis for the P365-Flux is made of polymer, which differs from the current aftermarket P365 Flux Raider offering, which is metal. The FCU, slide, and internals are all standard P365 parts. The barrel length is 6”, which is considerably longer than the standard 3.7” barrel that you'd find on a P365XL, and is actually longer than an HK MP5K barrel.

The firearm features a removable barrel shroud, which I'm sure is designed in conjunction with the barrel to prevent you from blowing fingers off. You do not need to remove the shroud to field strip the pistol, which is nice. It can cause a pinch point, so be careful when manipulating from the front slide serrations. It allows for a much-needed spot to place your thumb while firing, and keeps my digits in place, so I'll have them, which is important because I need them for work at the PowerPoint factory to feed my hobby of turning money into noise and the smell of burnt gunpowder.

The chassis features a forward mag carrier that allows you to carry extra ammo on the gun. When there's a fully loaded mag inserted, it adds a little extra weight to the front to tame muzzle rise. The firearm is well balanced with or without a full mag in the forward position, and doesn't feel front-heavy to me. There's a button on the backside of the mag carrier that allows you to drop the magazines. A half press drops the front mag, and a full press drops both mags for ultra-fast reloads.

There’s a brace deployment latch on the front mag carrier. Hitting the latch with your right index finger releases the brace, which is spring-loaded with a nice, strong spring. It takes seconds for the brace to flick out and lock into place. It allows for super-fast brace deployment without awkward hand positions.

The FCU has ambi safeties and an extended slide stop/slide release. The safeties are pretty thin. If I were to use the safeties, I might invest in larger safeties, which are available on the aftermarket. The standard ones are usable. They also don't block access to the slide release, which is nice, but I have to ask myself if they’re meant to be safety levers or if they’re just legally required to be there. The FCU also features a flat trigger, which is preferable in my opinion.

The optic is a fully enclosed SIG Sauer Romeo-X SIG-LOC compact. I’ve been a fan of the Romeo red dot pistol optics, and this one is no exception. It has clear glass, three reticle options, a side-mounted battery, and the new “SIG-LOC” mounting design. SIG-LOC is SIG’s newest optics mounting pattern, and they claim it’s the strongest lockup in the industry. It has five points of contact and screws in from the bottom of the slide. It seems very robust and allows for co-witnessing with irons.

Specs:

• Capacity: 25 rd mag included. On-board mag carrier could bring the total round count to 50 + 1
• Weight: 49.2 Oz
• Size: 19.1” Length x (1.34” deployed) or (1.52” folded) Width x 7.75” Height
• Barrel Length: 6”
• Accessory Rail: 1913 Picatinny
• Optic: Fully enclosed red dot optic with co-witnessed XRAY3 Day / Night Sights
• Note: all dimensions taken from the manufacturer's website.

Big performance, small package

In an electrical circuit, a capacitor is a little component that stores energy for use when the circuit is bogged down and needs a little extra juice. It’s like a little mini battery that augments the main circuit’s power. In the same sense, the P365-Flux, with its onboard 42 rounds, stores a lot of energy that can be tapped for situations that call for more firepower. It’s no full-size rifle with full-size rifle ballistics, but it is a great little package that performs well and is super efficient. In fact, I don’t think you’ll find more firepower in a package that’s more compact and controllable in today’s market. It’s great for situations where you probably won’t have a full-size rifle, but might need more than a pistol. Personally, I think they should have named it the Flux Capacitor, but I think the name may have already been taken. Great Scott!

I shot the P365-Flux alongside a long-slide VP9 and a P365X. I chose the VP9 long slide because it’s one of the most accurate pistols in my collection. It has a long barrel and the famous HK O-Ring to help with accuracy. It had been a few months since the last time I had been to the range, so I was a little out of practice, which is exactly what I wanted for this test.

I started cold and shot the P365-Flux and VP9 at 10 yards, then at 25 yards. The P365-Flux, with its three points of contact, gave a tighter group at 10 & 25 yards. After warming up, I ran the drill again, and the P365-Flux scored more points at 10 yards, but the VP9 barely edged it out at the 25-yard line. I found that I could relax a little bit with the Flux, whereas when shooting a full-size pistol, I had to be on my A-game as far as grip and trigger pull to have my shots land where I wanted them to be. I may have relaxed a little bit too much at 25 yds with the Flux, or may have warmed up enough with the VP9L, who knows. I think less experienced pistol shooters, and out-of-practice pistol shooters, stand to gain the most performance benefits from the Flux.

I later did double taps, and the P365-Flux won hands down in the category. The red dot hardly left the target under recoil. I will say the full-size pistol was a little bit more comfortable to shoot, recoil-wise. The recoil on the P365-Flux was sharp, but not terrible. The P365-Flux outperformed the super compact P365X by a wide margin.

If you were to compare the P365-Flux to a full-size PCC like the MPX or an MP5, I think you could probably shoot about as fast with the P365-Flux. I’m positive you could reload a P365-Flux much faster than an MP5. I think the MPX and MP5 are much more pleasant to shoot, though. A bigger and heavier PCC is going to be softer shooting; there’s no free lunch in physics.

I think performance-wise, the P365-Flux did great. I shot on a flat range at stationary targets. In a real-world scenario where you may have to use a handgun for self-defense, targets are going to be moving, and you’ll also probably be moving. There would probably be a lot going on situationally, and you may not have the best pistol shooting technique at the moment. The extra points of contact that the P365-Flux provides are going to be king in high-stress scenarios where fire superiority by volume is needed, or target tracking under less than ideal situations is required. You can also shoot the P365-Flux one-handed easily with or without the brace deployed, and you can’t say the same for a rifle.

Concealibility

I did not receive a holster with the loaner gun, but I did tuck the P365-Flux into my pants. I think it can be concealable with the right holster and body type. I think the gun would have to be carried appendix and high above the waistband. I think it’s doable, though. It’d be great if the chassis came with an option to mount a bungee sling for under the coat carry. The firearm should fit well in a fanny pack, and I think they make sling bags as well. Flux does offer a combo inside the waistband / outside the waistband holster. The firearm is really meant to be a concealable PDW, and I think it’s at the upper limit of that. Any larger and I realistically probably wouldn’t carry it. Any smaller and you’d be making sacrifices in the firearm design. As it sits, it’s not as comfortable as throwing a 38 Special in a pocket holster, but it’s concealable. Even though it’s larger than a standard P365, it’s the most concealable PDW SIG offers, and probably the most concealable on the market. Add a jacket and the Flux holster, and I’m sure most people would be able to carry it on their body if needed.

Cons

The firearm does have some sharp lines from the molding. There is a sharp line under the trigger guard that contacts my support hand when shooting the pistol with the brace folded. There are also a few sharp lines near the bottom of the trigger shoe, and my finger rubs them when shooting with the brace folded. The chassis is made of polymer, so 5 minutes with some fine-grain sandpaper or a Dremel with a polishing wheel would solve the issue. The trigger guard is also somewhat small, but not terrible. Other than that, it’s hard to complain.

Conclusion

I got some looks and compliments at the range. After showing one guy the 25rd mag, he asked who I pissed off jokingly, but liked the gun. Some people will look at the P365-Flux and may not know what to think about it. They may call it excessive or look at it like a novelty. It is new and different, but it is also a really great self-defense tool. The P365 has a good reputation for being reliable, and Flux Defense has made a great name for themselves by innovating and making great chassis. The additional points of contact and ability to stow an additional mag on the gun are undisputable performance benefits. The gun is on the upper end of concealability, but is still concealable. It’s a little bit over the top, and I might not carry for the usual run to the beer store, but it is what I would want to have as an option if I were facing a very real armed threat.

Read more about the SIG Sauer P365-FLUX on SIG’s website here: P365-FLUX

Stay connected with SIG Sauer on social media: SIG Social Media

Interested in reading about the TFB’s experience with other SIG Next products, or other SIG Sauer products in general? Check out these articles:

• TFB Review: SIG Sauer P226-X Legion SAO Pistol | thefirearmblog.com
• TFB Review: SIG P211 - 5,000 Rounds Later | thefirearmblog.com
• NEW Flux Raider 365: Full Review & Accuracy Comparison | thefirearmblog.com
• New P365-LUXE .380 - SIG Sauer’s Softest Shooting P365 Ever | thefirearmblog.com

We are committed to finding, researching, and recommending the best products. We earn commissions from purchases you make using the retail links in our product reviews. Learn more about how this works.