The firearms industry is continually saturated with one trend after another due to the ongoing development of new platforms and upgrades to existing platforms. In the past several years one particular platform that has exploded in popularity is the AR 15 pistol. One of the platforms leading the pack in this niche is the Maxim Defense PDX.
A combination of new product designs and some not-so-popular statements from the ATF have propelled these firearms into mainstream use.
If you have considered buying an AR 15 pistol, you may wonder what the hype is, what exactly is the definition of an AR 15 pistol, and if it’s worth even having? Let’s discuss the benefits of owning and using this platform.
The Legal Definition of an AR Pistol
The AR15 at its heart is a rifle and carbine platform. So how can there be such a thing as an AR15 pistol? The difference lies in the application of the National Firearms Act of 1934.
According to the National Firearms Act (NFA), a rifle has to have a minimum barrel length of 16 inches, or it is considered an NFA weapon and requires a $200 tax stamp in order to own legally.
While not impossible to get, the $200 tax stamp takes a long time to acquire (upwards of a year in some cases), requires you to pay an additional tax, and NFA weapons such as the AR 15 pistol are more heavily regulated than regular rifles.
Therefore, an SBR rifle comes with the hassle and expense of being classified as an NFA weapon. An AR 15 pistol, on the other hand, is classified differently, even though they are essentially the same thing as an SBR Rifle; ridiculous I know.
The primary difference is that an AR 15 pistol cannot legally have a rifle stock attached to it. Without a traditional rifle stock, this platform is legally considered a pistol and treated as such.
The debate that has gone on in recent years over the AR 15 pistol platform is related to the use of "pistol braces", which by design can mimic a rifle stock.
Therefore, the argument has always been, is an AR 15 pistol a pistol if it can be shouldered like a rifle?
There has been a good deal of debate over whether or not it is legal to shoulder an AR 15 pistol. Several letters from the ATF have both clarified and confused the issue. Clear as mud. I think that’s the way they prefer it to be. It gives them room to interpret the law as they please.
Therefore, AR 15 pistols are still classified differently than SBR rifles. If you choose to own an AR 15 pistol, get up to speed with the legalities of adding certain accessories that are common on rifles. For example, a vertical fore-grip is an illegal addition to an AR 15 pistol. I know that sounds absurd, but ATF regulations are hardly a place to look for logic.
The most obvious benefit of the AR15 pistol platform is that it gives you the advantages of an SBR rifle without needing to go through the long-drawn-out process of acquiring an NFA weapon.
Going from a 16-inch barrel down to a common pistol length such as 10.5 inches makes the gun substantially more portable and maneuverable.
Shorter barrels work particularly well within vehicles or confined spaces. The shorter length of the AR pistol platform, which combines a short barrel with a brace or simply the bare buffer tube rather than a stock, makes the gun very easy to pack into a Vertx backpack or duffle bag.
An AR 15 pistol allows you to legally carry a more capable weapon loaded and at the ready within a vehicle.
Some states do not restrict long guns in vehicles for those with a carry permit, so the AR pistol has an advantage here.
With that said, do not rely on the average cop to know all the specific legalities of owning and carrying an AR 15 pistol. Driving with an AR 15 pistol next to you may not bode well for you if you get pulled over.
Running a Suppressor
An indirect benefit of the AR 15 pistol platform is that it’s great for utilizing a suppressor. Not because it works better with a suppressor, but because the additional length of the suppressor body has less of an impact on overall length.
On a full-length rifle, that extra length and weight of a suppressor make a big difference in the handling and maneuverability of the weapon. With an AR 15 pistol, you’re still not approaching the minimum rifle length of 16" when you add a suppressor.
An AR-15 rifle with a 16-inch or longer barrel has no problem generating velocities approaching 3,000 feet per second. On the other hand, an AR 15 pistol, with its shorter barrel length, won’t be able to generate those velocities, so you won’t get the same ballistic performance.
Using a standard length AR rifle with standard 55-grain FMJ rounds, the average velocity is in the 2,850 to 2,900 feet per second range when measured 15 feet from the muzzle.
The same ammo fired from an AR 15 pistol platform clocks in at an average of 2,631 feet per second. That’s a velocity "loss" of about 250 feet per second. When you consider the roughly 5.5" difference in barrel lengths between the two platforms, that works out to a velocity reduction of about 45 feet per second per inch of reduced barrel length.
Regardless of the extremely short length, Maxim Defense has engineered the PDX barrel to be both reliable and accurate for its users.
The barrel twist rate of the PDX chambered in 5.56 is 1:7 (178mm)
The preferred load for the 5.5" barrel with a 1:7 barrel twist rate is the NATO M855 62gr ball
Using the NATO M855 62gr ball ammo with a 1:7 barrel twist rate results in a max effective range of 200 yards for the PDX platform
If you want the benefits of the more compact AR 15 pistol platform, there are ways to mitigate the handling and ballistics drawbacks.
Different braces, buffer tube systems, and shooting techniques such as sling tension shooting can help with the control factors while different bullet calibers and loads can improve terminal ballistics at lower velocities.
The Maxim Defense PDX comes in a few different flavors in order to satisfy most needs.
Stay Tuned to the RE Factor Tactical Blog and be part of this all VETERAN-run website. Be sure to follow us on Facebook, Instagram, and LinkedIn for exclusive content and deals.