Have you ever shot a gun just one time and immediately knew you had to buy it? That was me with the Maxim PDX. Coming in at just under 19 inches, the PDX is offered in powerful calibers such as 5.56 NATO, .300 Blackout, and 7.62x39mm. 

My first time demoing a PDX was at the F.I.R.E. Expo in Florida. The Maxim PDX proved to be reliable and shot very well – despite boasting a mere 5.5-inch barrel. Shortly after the event, I had an incident that made me go from wanting to needing the PDX. 

While driving late one night in Florida’s Big Cypress National Preserve, the car ahead of me was driving abnormally slow, so I went to pass. Instead of letting me pass, they paced me on a narrow road with swamp on both sides. They weren’t giving up either. The car then swerved and hit me.

I backed off and a number of situations went through my head. My location was in a no service area. So if this person decide to take things further, my concealed carry gun of the day was a .380 with just seven rounds. It could only do so much. In the end, thankfully, the situation ended when they pulled into a driveway. But it left me with an uneasy feeling.

I reported the incident to a ranger, and there was nothing they could do. Part of the preserve is on an Indian reservation and is governed by its own – somewhat mysterious – laws. Hence, the idea that you need to be your own first responder was further validated.

Why the PDX?

The PDX makes a perfect CQB firearm. Designed for military applications, it is also ideal for home defense or as a truck gun. The brace/stock options, depending on if you choose a pistol or SBR format, allow for rapid deployment. There are no buttons to push. Just grab, tug, and go. 

Another very well throughout feature is the ability to set what length the brace/stock will be deployed at. This works in part with Maxim’s SCW system, which is the heart of the platform. The bolt carrier group is integrated with buffer weights to shorten the brace/stock to 4 inches, and buffer weights can be adjusted to further tune the gun. 

Your PDX Options

There are a few different ways to get a PDX. It can be transferred as a pistol, an SBR, or purchased as an upper build kit. I decided to use an upper build kit, which allowed me to build my firearm with my own lower receiver. 

The upper build kit comes with everything minus the lower, lower parts kit, and trigger. With an inexpensive Anderson lower, Mil-Spec trigger, and basic parts kit, I was able to finish building the PDX. Having shot a fully assembled PDX before, the real question was if there would be any noticeable difference with the build kit: One was not noticed. 

Breaking in the gun at the CompExpo in Grand Junction, Colorado, everyone was tickled to shoot a 5.56 through such a short barrel. With a loud, deep bark and bright muzzle flash, the PDX drew curious onlookers. Recoil is almost non-existent for the shooter because the Hate Brake muzzle booster does a phenomenal job of keeping the muzzle flat, chewing up spent gas, and pushing the concussion away from the shooter. 

The efficiency of the Hate Brake was further tested when a lefty fired the gun. Generally, righty-built direct impingement systems send a lot of gas into the face of lefties. Not this one. Now, the claim of decreasing the flash signature might seem questionable as this gun seems to push cannon balls out the end, but it must be better than without the break on such a short barrel. 


Common feedback was that this is a fun gun. Despite the very short barrel pushing out 5.56, it was a cream puff to shoot. I explained to our testers that this was my gun and there is zero reason to hold back on thoughts. The goal was to break it in and see what the PDX is really about. The PDX got no complaints, except from the people not shooting – It is loud!  

The PDX is small enough to fit in a backpack – a great idea for school resource officers – and powerful enough to handle serious situations. This is hands down a reliable gun, which is a unicorn for small guns chambered for the calibers the PDX offers. If you’re looking for a first response gun, the Maxim PDX is the answer. You can choose from an array of build options and calibers. Just be sure to check all local and state laws on how to transfer and transport the various types of firearms.

Taylor with Maxim Defense PDX in hand outside
The Maxim Defense PDX upper kit allowed me to make a very compact self-defense firearm. (Photo: Taylor Thorne/Guns.com)


Maxim PDX on wooden beam
Buy one or build one, either way the PDX could be your best friend in a pinch. (Photo: Taylor Thorne/Guns.com)

Banner image: Taylor Thorne/Guns.com