How to Choose the Best AR 15 Caliber

How to Choose the Best AR 15 Caliber

How to Choose the Best AR 15 Caliber

When the AR platform was introduced more than a half-century ago, your caliber options were limited to 5.56 or .223, but a lot has changed since then.

Due to the rise in the platform’s popularity and the advances in both cartridge innovation and product design, the AR is now available in an almost dizzying variety of calibers that are suited to different purposes.

We’ll take a look at some of the most common calibers for the AR-15, what they’re best used for, and how to decide which one is right for you.

Best AR 15 for Long Range

The definition of “long-range” varies from person to person, but in this instance, let’s say that we’re talking about a distance of at least 100 yards – often 200-300 yards in some cases and far beyond that in others. The AR-15 really shines at that kind of distance – almost as if it were originally purpose-built for it.

5.56 / .223

The original calibers for the AR-15 were the 5.56 on the military side of things and the .223 on the civilian market. There are slight differences between the two, but in layman’s terms, they’re practically the same, and they are a great choice if you’ll be shooting at 200 yards or more.

.308 Winchester

The .308 cartridge has been the go-to for long-range applications for decades. While technically this bumps things up into the AR-10 categorization instead of the AR-15 categorization because of its larger size, it’s definitely still applicable here in terms of the parent platform. You can easily reach out to 800 yards or more with a .308 cartridge.

6.5 Grendel

The 6.5 Grendel cartridge has a lot of things going for it when it comes to long-range applications. It offers significantly more energy than 5.56 / . 223 rounds, produces less recoil than a .308 Winchester, and is useful out to 1,000 yards while still maintaining decent terminal ballistics.

AR 15 Calibers for Protection & Defense

Self-protection and home defense have never been more important in the crazy world in which we live today, and so it only makes sense that one of the most popular firearm platforms out there is also used in these situations.

Of course, you’ve also got to choose the right round for this purpose. A cartridge suited for long-range shooting is wildly inappropriate for a home defense situation, where distances rarely exceed 25 yards.

.300 Blackout

One of the biggest benefits to the .300 Blackout cartridge is that it pairs so well with the use of a suppressor, which can be a big benefit if you have to shoot your gun in your home. Make no mistake, though: it’s a very powerful round, and you’ll need to be mindful of possible over penetration both in the home and in urban situations beyond.

Pistol Calibers

In addition to the rise in popularity of the AR pistol as a platform, so, too, has the popularity of ARs chambered in pistol calibers such as 9mm and .45 ACP. This gives you the convenience of availability and cross-platform compatibility that is hard to match. Everyone knows pistols are more accurate the longer the barrel, and so it only makes sense that an AR pistol with an 8″ or 10″ barrel is a solid choice for protection and defense.

Best AR 15 for Short Range

Like long-range, the definition of “short-range” also varies, but for these purposes, we’ll say that short-range is anything inside of 200 yards. This could include self-defense situations and a whole host of hunting scenarios.

5.56 / .223

In the same vein as the long-range mindset, the original 5.56 or .223 calibers are ideal at distances under 200 yards. Of course, there are definitely some trade-offs you’ll have to make if you plan on using the same cartridge for both long and short distances, but if you’ve only got one caliber option, there are certainly worse choices to be made.

.300 Blackout

Once again, the .300 Blackout is a great choice for an AR-15 at short-range distances. Unlike home defense situations, you won’t really be concerned with overpenetration here. The .300 Blackout is a solid choice in caliber for short-range situations, and it’s also a lot of fun – especially when it’s suppressed!


If you’re looking to do some pest control or just have some fun plinking, there’s hardly a better caliber out there than the .22LR mainstay. This is also a great way to get in some training and muscle memory development with your larger-caliber AR at a price point that is much more budget-friendly.

Other Considerations for Choosing the Right Caliber AR 15

Aside from determining when and where you’ll most likely be using your AR-15, there are a lot of other things to consider when choosing the right caliber for your AR platform firearm.

Availability of the Guns & Ammo

The AR platform in and of itself has never been more prevalent, so finding a standard AR in a 5.56 / .223 chambering is unlikely to be an issue. Finding the necessary conversion parts for other calibers, or even ready-made guns in different calibers, however, could prove to be more of an issue.

The same goes for the different kinds of ammo for those other calibers. Some are much more specialized than others and it can be hard to find certain ones when you need them most. This is even more true in the current ammo situation where supply is often sparse.

The Prices of the Guns & Ammo

Again, a standard AR-15 isn’t going to be expensive. Sure, you can spend thousands of dollars on one, but you definitely don’t have to do that in order to get a reliable firearm.

Once you start moving into the realm of entire new guns for these different calibers, the prices start going up. You can also choose to swap out the necessary parts and reuse the “plug-and-play” parts of your base AR-15, but even then, prices start to add up – especially if you’re going to go with a bunch of different calibers.

You’ll be seeing lots of dollar signs when you start amassing different calibers of ammo, different magazines, different upper receivers, etc.

Find the Best AR 15 Caliber for Your Weapon Needs

Hopefully, the information above has given you a lot to think about and has helped you narrow down the best caliber or calibers for your next AR-15 purchase.

The next logical step after picking your caliber is to pick your suppressor, and at Silencer Central, it’s never been easier to get the right suppressor for the right caliber in your AR-15. Give us a call and let us know what kind of setup you’ll be using and in what caliber, and we can recommend the perfect suppressor to go with it.

Just like the AR-15 is compatible with a variety of calibers, so are many of the suppressors that we sell. You don’t have to be limited to one suppressor for one rifle in one caliber. Let us get you on the path to suppressor ownership for all of your multi-caliber AR needs today!