The Flux Defense Raider 365: Covert, Compact, & Capable

Since the creation of both long arms and handguns, people have been looking for a way to split the difference. Though this has taken many forms over the years, we certainly know where Flux Defense pens the line.

The goal of Flux Defense continues to be to give someone the draw speed of a handgun combined with the accuracy and stability of a subgun — all without making it as large as a rifle. This plants Flux Defense and their wares into the Personal Defense Weapon (PDW) category of the continuum. 

What you see here is merely the latest in a long line of continuous development. Flux’s first SIG PDW conversion, the MP17, was featured in CONCEALMENT Issue 16. The improved MP17 Raider Gen II not only graced the cover of CONCEALMENT Issue 22 but still sees regular use on the range and the road — in fact, that Raider Gen II is so highly regarded you’ll not only occasionally get a glimpse of one in the hands of covert forces but also SIG Sauer themselves is now offering a P320-FLUX Legion.

All of this to say: everything you see here is rational and useful. While they can be cool range toys, they’re all primarily practical. And Flux Defense approaches them as such.

LEGALITY & LOOPHOLES

As a forewarning, we’re just going to use the word “stock” instead of playing legalese language with the word “brace,” even though the version shown is ostensibly a braced pistol. We went through the trouble of registering a SIG P365 FCU as a short-barreled rifle, so it doesn’t matter if/when the Supreme Court strikes down brace bans and other Trump-era gun control. FWIW, it does work as a brace, too.

If you want to trust that all law enforcement officers you interact with will be up to date with every legal proceeding or won’t care about violations, that is 100 percent your right and your choice. You might beat the charge, but you can’t beat the ride.

Here, we simply avoid the asterisk entirely by registering; for more information on DIY Form 1 guns, see “Death and Taxes” by Tom Marshall in RECOIL Issue 44. 

DESIGN DETAILS

The Raider 365 is a chassis for your SIG Sauer P365 that adds on a quick-deploy stock for stability (which is important for accuracy) as well as doubling (or more) the ammunition capacity. Our version is a mere 9.75 inches long when folded, 18.5 inches extended.

INSTALLATION

Installation is like any other P365 grip module. Which is to say, easy. A single pin is all you need to push. The PITA P365 magazine release is pre-installed. While you can eschew your original grip module, you’ll need your complete slide assembly along with an optic to complete the ensemble.  

You’ll notice there’s a lot of space between the muzzle of the barrel and the end of the PDW chassis. You need something that’ll give you a stock long enough to use, which means you’re adding length to the front or the rear; Flux chose the front to accommodate their spare mag carrier. They included an optional barrel shroud (not the shoulder thing that goes up) to keep your thumbs from the muzzle. But you can put that space to work with a longer P365 barrel. Flux Defense has a 6-inch barrel for the Raider made by True Precision.  

CONTROLS

There’s a sliding button just forward of the triggerguard to pop the stock. A push forward with the trigger finger (or support-hand thumb for lefties) and the spring-loaded stock swings out and snaps in place. The switchblade action of the original Raider was one of its claims to fame, and while this one operates differently, it’s still quite satisfying to deploy.

A push button under the hinge mechanism unlocks the stock so it can be folded again. Though the spring used to launch is quite stout, it’s not too hard to fold because of the leverage involved. 

The controls closely match the full-size Raider, with dual magazine releases intended for the fastest swaps possible. There’s an ambi thumb release on the forward spare magazine and a left-side push lever, and you can drop one or both with each. 

With just a little bit of practice, you can grasp the spare, drop the empty, and make the switch like a pistol-gaming grandmaster.

It’s noteworthy to mention here that the Gen II Raider features a right-side mag release in addition to the levers on the left, but that’s deleted on the Raider 365 due to decreased space and to avoid confusion with the stock deployment.

Nothing about the Raider 365 touches the trigger on the chassis. As standard, you’ll use the same safety systems (or lack thereof) as the P365 you already own. 

Magazines

The grip is XMacro length, meaning XMacro and Fuse magazines are just fine. It’d be nice to have the ability to carry a 10 or 12 rounder, for compatibility if nothing else, but we’re not chomping at the bit to break out the angle grinder either. While SIG Sauer is now shipping 21-round mags, if you look at the aftermarket there are drums and sticks (YMMV). 

With the ability to carry a spare, it’s easy to have 30 rounds or more right there.

Length-of-Pull

Something we learned years ago with our Glock Stock Buyer’s Guide (see RECOIL Issue 44), the shorter your length-of-pull, the higher your optic needs to be. Unlike the larger P320/M17 Raider, the optic on the Raider 365 still rides on the slide. Flux Defense gets away with a shorter LOP without a skyscraper optic because of the downward angle of the stock assembly. You can get low enough to use your irons easily, which wouldn’t be possible if the stock arm were in-line with the bore. 

The Short version has a LOP of 13.5 inches and the Long has 15. In terms of braces and buttstocks, the buttstock model has a much larger, textured surface area intended for your shoulder. When the assembly folds up, the support end nests right against the front of the chassis. 

This means your light or laser may or may not work, at least not if you want to fold it. Because the tail is modular, there’s a possibility of other ends, but in the meantime an offset Pic mount can do the trick, albeit with a wider profile. 

OUTFITTING

The slide is up to you. We tried everything from original models to the brand-new FUSE. Ultimately, we ended up with a XMacro-Comp slide with a chameleon Faxon match barrel inside. 

For an optic, we wanted it durable with a large window, so we went with an Aimpoint ACRO P2 with an Atibal conversion plate. It works extremely well in this setup, and the little extra height was just right.

Which Raider 365 model you have limits your light or laser. Our Short sits flush with a Streamlight TLR7sub, SureFire XR1 (our choice), and Nightstick TCM-550XLS; you’ve got about 2.5 inches to work with. SIG’s Foxtrot2R almost makes the cut, and we bet future models will fit SIG stuff. The Long model sits and fits flush with a SureFire X300U and similar. 

HOLSTER

Usually when we talk carrying compact PDWs, the go-to is a cinched sling. But the Raider 365? It’s small, it’s thin, and you can carry it AIWB. The original MP17 chassis had a holster but there was a lot of room for improvement.

The Raider 365 has the Two-For-One holster not because of the dual magazines (though that applies) but because it can do double duty both inside and outside your waistband, with or without a WML.

And while it’s larger than a typical AIWB setup, it’s not an impossible problem. If you find it’ll be too much in your pants, it’s easy to stow in a sling bag or even a Vertx SOCP fanny pack. 

ON THE RANGE

It should be no surprise that the Raider 365 ran well with everything; SIG’s P365 is the most popular 9mm in history for a reason. 

Formal accuracy testing is going to greatly depend on your barrel/slide/ammo setup, but we’re the type to shoot regular handguns at over 100 yards (long range pistols are great at exposing flaws) but even the unaccustomed can easily do that here.

The dot is easy to track under recoil, especially if you have a second hand for support. 

If you’re worried about the slide breaking your face, don’t. There’s a safety stop on the bar to let you know exactly how close your face can safely get without eating a slide. It makes for an excellent index point.

LOOSE ROUNDS

It makes sense that Flux Defense is focusing more on SIG’s P365, because even SIG themselves is spending considerable time there, too. With the advent of the P320-FLUX Legion, I expect some other models will receive similar treatment as Flux Defense and SIG continue to work together. 

There are plenty of rifle-sized PCCs that shoot pistol projectiles, but you end up with the size and snags of a rifle with none of the ammunition advantages a rifle can bring. Worst of both worlds. But the Raider 365? The opposite. 

Just because it’s not pragmatic for you doesn’t mean it isn’t practical. But then again, it probably is practical for you, too. 

The Raider 365 is fast, accurate, and controllable. 

It is more capable in almost every metric (speed, control, capacity, accuracy) than a handgun alone. 

It conceals easily, both on your person or off-body in a bag or vehicle. 

Sometimes you simply need a rifle to solve rifle problems. And there’s no one saying you can’t have a rifle if you have a Raider. But that large gap between a pistol and a patrol carbine?  We’ll try to find something better, but it’s going to take some looking. 

Great damned job, Flux Defense. 

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