Ever heard of the AR40? You’ve likely heard of the AR-15, AR-308 and AR-10, but the AR40 is a bit more of a niche build. Consider this your primer.
What Is an AR40?
The term AR40 is a bit loosely defined (and it also competes with other entities on the market) but for the purpose of this article, the term AR40 refers to an AR-style platform chambered in .40 S&W, generally one that is of an ARP, or AR pistol footprint.
When compared specifically to other handgun-caliber AR builds, the AR40 offers a few unique advantages, as well as some over rifle rounds. Here’s what you should know.
Why Choose an AR40 Upper?
Thinking about building with an AR40 upper? Here are some of the biggest advantages of going this route, and choosing the .40 S&W in general.
- Power: Power is one of the main draws of the AR40, not as it compares to rifle-caliber rounds (because, as a handgun round, .40 S&W is lacking compared to rifle caliber rounds) but because it is better than many other handgun rounds in which PCCs and ARPs are commonly chambered.
Compare it to the 9mm, for instance. The 40 S&W produces higher muzzle energies, around 400 ft-lbs, whereas 9mm produces energies closer to 340 ft-lbs. Bear in mind that bullet weight and load data will influence this, but regardless, the .40 produces a larger wound and delivers more energy to the target.
It costs a little more and produces more recoil, but that’s a small price to pay for the extra energy.
- Compact size: The AR40 is generally produced as an ARP, not as a carbine. Therefore it carries the same benefits of other AR pistols. It is smaller, lighter, more compact, and thereby easier to conceal, than full-size ARs. This makes an AR40 a great platform for defense applications.
- Handling: Smaller and lighter than a carbine, an AR40 will offer lighter, superior handling, especially in tighter quarters than a full-size platform. This underscores its suitability for defensive applications, such as for home defense or as a truck gun.
- Recoil control: The .40 S&W produces only as little more recoil than the 9mm, and the heavier mass of an ARP-style platform will help absorb some of that recoil. This makes an AR40 a solid choice on those grounds. Consider also that an ARP can be outfitted with a pistol brace that will aid in one-handed stabilization and shooting.
- Versatility: The .40 S&W cartridge has numerous use cases ranging from sport shooting to defensive applications and even hunting, where legal. Being more powerful than 9mm, it is considered by some to be more effective for defense and sporting uses.
- Uniqueness: The AR40 is a relatively unique choice for an AR pistol build, making it a cool choice for tinkerers and builders that already have ARPs in 9mm or 5.56 or who have already built PCCs.
- Customizability: Like other AR-style platforms, the AR40 is customizable, and we carry a variety of AR40 parts as well as shooting accessories that you can use to personalize your build, regardless of what you ultimately settle on.
Can .40 S&W Stop a Bear?
One of the most common questions about the .40 S&W cartridge has to do with its suitability for stopping a bear. It’s probably inadequate for a grizzly, but with a steady hand and good shot placement, .40 S&W can potentially be effective for defense against a black bear. There is a debate also with regard to whether HP or jacketed rounds are better; HP dumps its energy and produces a wider wound channel but jacketed bullets will penetrate deeper. Ultimately, shot placement is more critical here.
Are There Any Drawbacks?
Now let’s take a look at some of the concessions you’ll have to make if you build an AR40.
- Limited power and range: While the .40 S&W is more powerful than 9mm, it is not as powerful as rifle-caliber alternatives like 5.56 or .308, regardless. It lacks not just the range but the power, so that is something to keep in mind.
- Accuracy: Being a handgun cartridge, .40 S&W is also inherently more unstable at range than rifle bullets. At intermediate and extended ranges, a rifle caliber ARP will likely shoot more accurately.
It’s a Tradeoff
Ultimately, an AR40 makes sense for you only if it meets your needs. There are just as many potential advantages to rifle caliber ARPs or those chambered in other more common handgun cartridges like 9mm.
Explore AR40 Uppers and Parts Here
In the market for an AR40 upper? Looking for AR parts or accessories to complete the build? Check out our collection and if you need help finding something get in touch with us at Sales@MCSGearup.com.