Many AR pistol uppers are chambered in rifle calibers, which makes sense. One of the main draws of an ARP is that it offers rifle firepower in a more compact format.
Some are chambered in 9mm or other pistol calibers, and there are many PCCs, or pistol-caliber carbines as well. Many of these are actuated by gas systems like standard ARs.
Then there are bufferless 9mm AR uppers that are chambered (obviously) in a handgun caliber, and which lack gas systems.
These are a unique class of ARPs, and they just might be your favorite yet.
Compactness
One of the coolest things about bufferless 9mm AR uppers is that they can be made much more compact than any with gas systems. If you want to build a truly micro ARP, this is one of your best options.
The reason for this is that standard ARs have a gas system, which requires a buffer system of weights and springs that are housed in a buffer tube, which returns the bolt carrier group to battery after firing.
Bufferless 9mm AR uppers typically utilize direct blowback operation, in which the mass of the bolt face and pressure of the recoil spring holds the action closed until chamber pressure builds sufficiently to force the bolt back and cycle the action.
They do not require a buffer tube and so they can be much lighter and far more compact than ARPs with buffer tubes, making them ideal for concealment and use in defensive encounters.
Simplicity of Operation
Another great thing about a direct blowback system (for all its faults, and there are some) is that the action type is a lot more simple than a gas system.
A gas system must be kept clean, and the gas rings and other components wear out. In addition, they rely on a series of buffer weights and springs to cycle the action.
There are many more parts to a gas system, each of which must be tuned in order to run the rifle optimally, ensuring consistent, smooth cycling and easy ejection.
Direct blowback certainly has its shortcomings, but when used with a relatively low-pressure cartridge like 9mm, it’s reliable enough, and its simplicity is a selling point.
Low Cost Ammo and High Availability
Now that we’ve covered some of the selling points of direct blowback operation, there are numerous draws of building a 9mm ARP that should also be highlighted.
One of the biggest draws of 9mm is that every major manufacturer loads it, which keeps prices down. If you buy in bulk, you can get 9mm for 30 cents per round or even less, even with prevailing high prices.
Cost is one thing, and it makes 9mm attractive, but availability is also a big component of this, and 9mm, along with .22LR, 12 gauge target loads, and .223/5.56, is one of the more highly available cartridges in the industry. Chambering your ARP in 9mm means you likely won’t ever have a hard time finding ammo.
Great Performance for Defensive Applications at Close Range
Pretty much any rifle caliber, even a small one like 5.56, is going to deliver more stopping power and perform better beyond 100 yards than 9mm.
But the big thing about 9mm is not its long-range performance. It’s what it can do up close and how effectively it can dump energy. Compared to spitzer rifle bullets, 9mm fires a big, wide, heavy bullet that hits hard up close and is designed to dump its energy. This makes it an excellent defensive cartridge, especially with +P rounds, and even more so in close quarters.
On top of that, 9mm produces fairly little recoil, even as handgun cartridges go, making it suitable even for beginners and smaller-framed shooters.
Less Risk of Overpenetration
There is one other aspect of 9mm as a defensive round that makes it highly attractive, especially when compared alongside rifle calibers. Though rifle calibers will hit harder, they are also generally intended to penetrate further. A handgun cartridge can solve some concerns associated with that.
Unlike cartridges like 5.56 and 7.62, 9mm will dump its energy effectively without overpenetrating in most circumstances. This makes it highly suitable as a defensive cartridge, especially when used indoors and in close quarters. That’s just one more reason to build with a bufferless 9mm AR upper.
Shop Bufferless 9mm AR Uppers Here
Thinking you want to start your next build with a bufferless 9mm AR upper? Shop our collection; we carry a wide range of micro ARP uppers and parts, along with bufferless uppers. Take a look through what we offer and if you have any questions about components or compatibility before you buy, get in touch with us at Sales@MCSGearup.com and we will be more than happy to help.