We love Pistol-Caliber Carbines. Our veteran writer owns four of them, two being AR 15-based 9mm rifles. PPCs have become increasingly popular in the United States and it's easy to see why: A 9mm AR 15 makes for a perfect regular or 80 lower build, and it can be done with a standard built or 80 lower and an AR 15 pistol kit or a rifle kit! Converting a standard lower to a pistol-caliber magazine well means simply buying an adapter that changes the internal dimensions of the mag well. These adapters are made by Colt, Promag, Tork Mag, and many other rifle and AR 15 magazine companies to adapt the mag well to Colt SMG magazines, or even Glock magazines. Because of this, you can still make your own PCC by machining a regular old 80 lower using all the parts you would for an 80 lower rifle build!
The Pistol-Caliber AR Advantage
So, why bother? Pistol-caliber ARs can be either 16-inch rifles, SBRs, or pistols. We prefer the pistol because a rifle barrel is unnecessarily long for a pistol caliber. There are some serious advantages to having a pistol-caliber AR. Here are our top reasons for making a pistol-caliber AR out of your 80 lower build:
- Lower Recoil
- Lower Muzzle Rise
- Easier to Suppress
- Low to No Muzzle Flash
- Can be Used at Any Indoor Range
- Can be Built From a Standard AR Pistol Kit
They are excellent options for teaching new shooters the AR platform because they are so pleasant and easy to shoot. For home-defense, the lower flash, concussion, and noise make the weapon much easier to handle and to rapidly fire with control.
Building a PCC from an AR Pistol Kit
The first step is securing the basics of an AR 15 Kit. Remember, you’re firing a pistol caliber through a much larger weapon than it's originally designed for. With the ATF saying it's legal to shoulder a pistol brace like the KAK Shockwave, we don’t see a point going with a full-size rifle upper. We recommend sticking to shorter pistol barrels for 9mm carbines. (That being said, a pistol-caliber rifle is fun, and one of our writer’s first PCCs was rifle-sized.)
You can buy a specialized lower with a 9mm mag well, but there are issues with this: These stripped lowers are pricey and can be hard to find. They also use proprietary parts. Let’s look at our classic AR 15 Pistol Kit with a standard forged lower and full lower parts kit, and compare it to a specialized pistol lower.
Ours is at least 25 dollars cheaper and includes a lower parts kit. The lower will get you started, and you can use all standard AR components, including pistols tubes, rails, grips, and sights. Since it’s a pistol caliber there are some additional parts necessary when building the system:
The Necessary Parts
- Blow-Back 9mm Bolt
- Pistol caliber Buffer
- Pistol Upper Receiver (No gas system needed)
- Mag Well Adapter
Building a Pistol-Caliber AR, or PCC, is actually a little easier than piecing together a rifle because they are blow-back weapons. They don’t require gas systems like a standard AR 15. The PCC craze is in full swing and it’s a movement we’re happy to be a part of.DISCLAIMER: If you are new to the world of DIY AR-15 building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. We are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.