Most people buy AR-15 rifles, or build them, chambered in 5.56 or .223. After all, this is and has been the standard for the better part of a century at this point, and there are a lot of things to love about those intermediate rifle cartridges.
They are cheap, affordable, produce little recoil, shoot flat, which makes them great for long-range shooting, and they have a wide range of use cases between sporting and defensive applications.
But 5.56 and .223 are not your only options. You also have the choice to build a pistol caliber carbine or an AR pistol, in which case you should at least be considered 9mm. Here are the best reasons why.
Low Cost
In some instances, 9mm is actually not too far off from 5.56 or .223 in terms of price, but if you compare it to most other pistol calibers, as a general rule, it’s a lot more affordable. Also, since a lot of police precincts use it, you can often get it surplus at a great deal.
The low cost of 9mm means you can shoot it all day long without it banging up your wallet too badly.
Availability
Following right on the heels of price is availability. This one is pretty much the most widely available handgun cartridge out there. If there’s a gun shop, they sell 9mm, even if they happen to be temporarily out of it.
It’s Light and Low Recoil
One of the biggest considerations out there, especially if one of your goals is to get new shooters into the sport, should be recoil and recoil management.
The 9mm cartridge is a light recoil cartridge by any metric. There are lighter cartridges, like .22 LR and .380 ACP, but these also have limitations that 9mm doesn’t have.
This makes 9mm one of the best available to you.
It’s Versatile
You should also weigh the fact that 9mm has a lot of use cases. It is effective for defensive applications, high-volume target shooting, competition shooting, and in some cases, even for hunting - so that one caliber can do a lot.
It’s Compact
The cartridges themselves are fairly small and light, which makes it easy to transport a whole lot of them to the range. The other thing is that the magazines are also smaller and more compact, which makes it easier to carry more of them.
It Performs Well from Short Barrels
This is one of the better reasons to build an AR pistol around 9mm. You might be thinking that you’re making a compromise on firepower, and that is true, but you have to remember also that 5.56 and .223 don’t really perform well from short barrels and shoot really dirty. Being a handgun cartridge, 9mm is optimized for performance out of very short barrels. This gives you the edge if you are thinking about making a super compact micro AR pistol.
You Probably Have Other Guns in the Same Chambering
Just from a utilitarian perspective, if you have other handguns in 9mm, that should streamline your ammo supply chain. It alone is not a reason to build a pistol caliber carbine or an AR pistol in 9mm, but it’s a selling point nonetheless.
It’s Suitable for Defensive Applications
The 9mm won’t produce as much stopping power as a more powerful cartridge like .223 or 5.56, or even other handgun cartridges. But it has an edge over most rifle calibers simply because the cost of that lower stopping power is also a much lower risk of overpenetration. These bullets are heavier and fatter than rifle bullets and with an appropriate bullet are not likely to overpenetrate, even though that is no guarantee that they won’t.
AR Pistol Platforms Are Highly Expandable
One other reason to choose 9mm for an AR pistol build rather than a rifle caliber, even though it entails a big tradeoff in firepower, is that AR pistols are by their very nature highly expandable and in many ways much more so than relatively comparable handguns.
You’re lucky if you get a little section of rail under the barrel with a handgun chambered 9mm, but with an ARP, you can reap the advantage of a small quad rail that will give you plenty of options for mounting lights, optics and other shooting accessories and attachments.
Explore Pistol Caliber Carbine and AR Pistol Parts Here
Whether you ultimately decide to build an AR pistol, a pistol caliber carbine, or a full-size rifle, or you choose a chambering other than 9mm, we have the AR parts, including AR lower parts kits and assembled uppers, to make your project easier. Take a look through our full collection and get in touch with us at Sales@MCSGearup.com for more information.