This is the next article in a series on Truck Guns, or the firearms you might want to keep nearby in case of an emergency (or zombie invasion, whichever comes first). Earlier this year, Tom R. posted an article about the new Springfield Kuna. Unlike many articles and videos about the compact subgun (ehem, “large-format pistol”), he framed the weapon as a truck gun. That idea led me down a rabbit hole exploring what constitutes a truck gun, why someone might need one, and the different applications available. Someone living in the country versus someone in suburbia has different needs. The first article in this series covered a Ruger American in 300 BLK, perhaps the perfect truck gun for rural environments or urban sniping. The following article featured a fully equipped Mossberg 590, designed for individuals seeking flexibility in confined spaces. For this article, I wanted to focus on something you could build out of something you may already own and turn it into the ultimate truck gun machine.
First, what’s a truck gun? A truck gun—at least in my mind—refers to any weapon stored in your vehicle for defensive, hunting, or survival purposes. These firearms possess key characteristics, including versatility, compactness, and lethality. Of course, this definition is somewhat ambiguous, with many variables to discuss.
**Legal Warning** If you are interested in pursuing this concept, I would be remiss if I did not warn you to check local laws concerning the transport of weapons in vehicles, particularly long guns and NFA items. States with concealed carry or constitutional carry tend to favor handguns. Things can get spicy when long guns and other scary items are loaded in vehicles.
A PDW For Your Truck
Too many, a PDW, or personal defense weapon, checks many of the boxes for a truck gun. It’s handy and maneuverable. It’s easier to shoot accurately compared to a handgun. And it’s usually chambered in a caliber like 9mm—something that’s inexpensive to shoot and plenty capable within a hundred yards or so. This is why the Springfield Kuna excels in that role. However, you don’t have to buy an “off-the-shelf” PDW. Several of today’s pistols utilize independent “fire control units” that are serialized and separate from the pistol’s frame, providing users with flexibility. The Sig Sauer P320 was the firearm that mainstreamed that idea. As a result, several aftermarket companies have developed ingenious ideas to transform the P320 into a PDW.
Flux Defense
I’m unsure if Flux Defense was the first company to do this, but they were the first I saw and thought, “I need that.” Yes, I was influenced by a YouTube video. Yes, sometimes influencer marketing works. Do I hate that it worked on me? Maybe. But this tricked-out PDW is awesome. After firing many rounds, I find that the Raider X is a well-thought-out chassis system that elevates the P320 to a higher echelon (not to be confused with Springfield’s titular pistol, which also features a removable fire control system).
But don’t just take my word for it, take the word of the butcher himself (and if you got the Tommy Boy reference, we can be friends):
The Raider X is a compact Personal Defense Weapon chassis designed to push your SIG P320 beyond conventional handgun limits. It combines the speed and maneuverability of a pistol with enhanced control, stability, and extended capacity—delivering increased firepower in a duty-ready, concealable platform.
The Spec Sheet
Having already owned a stock Sig Sauer P320, I spent time researching and acquiring the necessary components and accessories to transform it into the ultimate PDW. Before I break it all down, here’s a list of everything (with links in case you are interested):
The Build
The build is as straightforward as it gets. Ensure the P320 is unloaded, drop the magazine, rotate the takedown lever, remove the slide, and then remove the takedown lever from the frame. From there, the FCU will pop out (sometimes you may need a flathead to help remove it, especially if it’s the first time). Then, plop it into the Raider, reinsert the takedown lever, and add the existing P320 slide. Voila. From that point, it’s all about accessorizing.
For optics, I selected the Holosun SCRS, which is mounted to an American Defense 509T QD mount. The optic is rock-solid, and I find it one of the best for people with an astigmatism. I then swapped the factory P320 barrel with a threaded model and attached a compensator from Herrington Arms to it. This helps mitigate recoil and promotes a linear impulse.
To improve ergonomics, I added the Flux side pic rails, which also serve as a thumb rest. This also helps with recoil management. Because the slide sits in the frame as it does, it can be hard to manipulate. Luckily, Flux designed the F10 charging handle. It replaces the front sight and allows for easy manipulation of the slide.
The final additions were a sling and a light. For light, I had a Sig FOXTROT2R, which is reminiscent of a TLR-7. For the sling, I added an Edgar Sherman Designs Sling. These are rather minimalistic and simple to use.
How Does It Function?
In short, flawless. It was easy to sight in and even easier to shoot. The brace deploys with force via a lever on the side. The front mag storage works just as well. Apply half pressure, and the spare magazine releases. Apply full pressure, and both the empty and spare mags are released. This makes operating the Raider X easy and intuitive to learn. Even the pistol grip is ergonomic and features a flared magwell. Honestly, I don’t have anything bad to say about it.
It’s also a people pleaser. Every time I bring it out, everyone wants to shoot it. Whether they are experienced shooters or novices, everyone enjoys it. But what about it as a truck gun? I think it fits the mold perfectly. Since it is classified as a pistol, it falls under the concealed weapons laws of many states. So, in Ohio, I can keep it hidden and loaded in my vehicle (as long as I follow the rules of where I can and can’t have it). While it might not be the best option for wide open spaces, I can deliver in a host of roles in urban and suburban environments.
Final Thoughts
If you already own a Sig Sauer P320, you are halfway to owning a capable PDW—no additional FFL visits are required. Just order online and have it shipped to your home. You get a compact and maneuverable package that provides greater effectiveness than a handgun. Is it the best truck gun for you? That depends. If it fits your environment, or if you don’t already own a P320, it may not be a good fit. But if you fall into that mold, I recommend you check it out.
In the following article in this series, it will cover another PDW-type firearm, but this time, I’ll discuss one of the many “chassis” systems available for Glock pistols. Will it be good? Or, will it be like many of the gimmicky options out there? Stay tuned.
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