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What Is a 300 Blackout Round & What’s The Ammo Good For?

L.p. Brezny | Updated August 4, 2023 | Why You Should Trust Us | How We Earn Money
What is a 300 blackout cover photo showing bullets piled on top of each other

In researching different types of calibers, you’ve probably come across .300 BLK ammunition. There’s a ton of information out there about this round, but we’ve compiled everything you need to know right here. 

So the question remains: what is a 300 blackout and what is it good for?

So, find out every advantage and limitation of .300 BLK and how it stacks up to other calibers.

More Reading: Best Optics For 300 Blackout

If you’re looking for more reading after this, I’d suggest you take a look at our article on the best optics for the 300 Blackout on the market.

What Is A 300 Blackout?

Advanced Armament Company (AAC) was tasked with coming up with a cartridge that could outshine the MP5SD and match and improve upon the characteristics of the AR-15 platform. The result was the .300 AAC Blackout military round, otherwise known as the .300 BLK or the 7.62x35mm.

Building upon the .300 Whisper platform, this round is specifically designed to be shot with a suppressor. As a new cartridge, it’s quickly becoming one of the most well-known alternatives to popular AR-15 cartridges on the market. 

When compared to the AR platform, the .300 BLK exhibits similar sound levels, albeit with more power. Both competitors, however, shine in many situations, from target acquisition and plinking in your backyard to hunting and home defense. 

How it Performs

Different bullets flying in opposite directions

Considered by some to be the upgraded alternative to the AR-15 platform, the .300 BLK does best in short-range shooting. It accepts both supersonic and subsonic ammo without the need to switch any equipment. 

As a projectile, this round is light, quiet, and hits hard. It’s limited to about 300 yards maximum due to ballistics, but it’s often a favorite choice for close-range combat. 

Due to the design of this round, it’s much easier to take advantage of the powder charge with a shorter barrel. The .300 AAC Blackout also burns powder faster than its .30 caliber siblings.

You can also easily suppress a rifle that shoots this round to gain even more advantage. In terms of recoil, you’ll experience about 9 pounds to the shoulder. 

When it comes to penetration, this caliber performs well. It’s ideal in hunting situations where you need to take down an animal but can be a burden to consider for close-quarter battles and self-defense situations.

Exterior & Terminal Ballistics

300 BLK gun aiming at a range

Compared to more well-known cartridges and modern bullet designs, this caliber has a slight edge in ballistic performance. With fatter, squatter, and heavier projectiles, the round can pack a hefty punch downrange. 

However, the round has a hard time reaching its optimal velocity. With a 100-yard zero, a 125-grain round travels at 2,240 feet-per-second (FPS) out of the muzzle with a 16-inch barrel. 

At 100 yards, that round carries with it 1,312 foot-pounds of energy. Just 200 yards down the road, that drops to 882 foot-pounds of energy. 

This increasing drop in energy is what characterizes this caliber’s ballistic performance. While it’s certainly a performer in short-range scenarios, it can’t quite reach maximum efficiency, even out of a shorter barrel. (Reference 1: .300 Blackout Facts)

Subsonic Ammunition vs. Supersonic Ammunition

Golden and silver bullets with different heights lined up

This round is classified as either supersonic or subsonic ammo. This ability to shoot both types of ammunition makes this round versatile for various situations. 

Most .300 AAC Blackout rounds of lower grain weight are supersonic. They travel faster than 1,125 feet-per-second (FPS) at sea level and typically reach a target before the sound of the round can. 

However, .300 BLK rifles can also shoot subsonic ammunition. With subsonic loads, hunters can avoid a sonic boom that warns animals of their intent before the round can reach them. 

So, shooting with either ammunition type is possible with an aerodynamic projectile like the .300 BLK. It can also help increase your choices regarding ammunition, what you take with it, and how loud you want your shot to be. 

Barrel and Twist Rate

Hands holding a brown and black short barrel rifle

A .300 BLK requires a 9-inch barrel and a quick twist rate for full ballistic potential. In other words, the powder charge within a .300 BLK round burns best at 9 inches of barrel length. 

If you were shooting a 5.56 NATO, you would need a 20-inch barrel to fulfill the same requirements. Over 20 inches of barrel, that round consumes the majority of the powder for the most energy possible out of the muzzle. 

However, you can convert your 5.56 to a .300 BLK if you’d like. All you’d need is a barrel change (at a faster twist rate) to join the many short-barreled rifles in this caliber. 

Regarding twist rate, the .300 BLK works best with a tight corkscrew in their shorter barrels. You’ll want to opt for a 1:7 or a 1:8 twist to take full advantage of this round’s potential. 

The .300 BLK round completes a full rotation in 7 or 8 inches with these twist rates. This, in addition to the shorter barrel length, often results in most .300 BLK short-barrel rifles acquiring the short-barrel rifle (SBR) classification.

If you plan on shooting supersonic projectiles with your new .300 BLK, choose the 1:7 twist rate. Go just a bit longer at 1:8 for heavier sub-sonic rounds. 

.300 Blackout Bullet Size

Fingers holding two different sizes of 300 blk bullets

You’ll have a wide variety of rounds to choose from with this caliber. This new cartridge is a 5.56 NATO that’s been necked down and stretched out.

In addition to supersonic and subsonic categorization, the most common .300 BLK round size is either 110 grains or 220 grains. Any grain weight in between is often used as well. 

300 Blackout Ammo Types

Nearly all .300 BLK ammunition types are known for their fast-burning powders that gain them leverage over other .223 calibers. However, with a .30 bore diameter, finding ammunition isn’t often an issue. 

It’s important to note that even though the .300 BLK is a necked-down 5.56 cartridge, this caliber will not shoot out of a 5.56. It might chamber in, but the results can be devastating. 

What is Blackout Good For?

Short barrel gun for close quarters combats

Like many other calibers of its kind, .300 BLK can be used for anything from plinking at the range to self-defense situations of life and death. You might use this short-barrel rifle for target practice in the off-season to keep your hunting skills sharp.

Many shooters use the .300 BLK for tactical training. However, it shines best when used in close-quarter battle situations and as a hunting round

The key here is a shorter barrel, fast-burning powder, a hefty bullet with plenty of energy, and the ability to shoot not only suppressed but also subsonic rounds. Add all these characteristics together, and you have an excellent hunting and home defense weapon.

AR platform gun and pistols scattered

.300 Blackout Effective Range

If you’re shooting inside 300 yards, you shouldn’t have any problems hitting your target with this round. However, if you go much beyond that, you’ll have issues with bullet drop and loss of energy.

That’s why most hunters use the .300 BLK in close range, typically 150 yards or less. If you’re looking to place your shot ethically, 250 yards is probably the furthest you’ll want to go. 

.300 Blackout Effective Range for Deer

Deer in a field

Small game, as well as medium to large animals like whitetail deer or feral hogs, can be taken with a .300 BLK at up to 150 yards. A game animal much larger than that requires a steadier round with greater energy and flatter shooting.

.300 BLK History

The .300 BLK stems from the .223 Remington and the 5.56 NATO. The two calibers retain a similar case capacity but vary greatly when it comes to twist rate. 

Created by Advanced Armament Corporation in collaboration with Remington Defense, it’s meant for use in the M4 carbine and is remarkably similar to the .300 Whisper.

Should You Chamber .300 Blackout?

There are many reasons to chamber your rifle in .300 BLK. The list of reasons why you shouldn’t is arguably just as long. 

One of the most significant issues with .300 BLK is the cost of ammunition. You’ll end up paying twice the cost of most 5.56 or .223 ammunition at most ammo dealers. 

Finding ammunition for modern bullet designs like the .300 BLK can also be an issue. Though .300 BLK is gaining popularity, it’s not as widely and commonly available as historical calibers.

Three different bullets lined up in a palm

It is entirely possible to reload .300 BLK ammunition. However, many shooters choose not to go this route because of the difficulty of necking down the 5.56 round. 

That said, the processes for prepping the brass are similar to what you would do for a .223 or 5.56 round. If you’re a hunter or avid shooter who does this already, adding another caliber to the mix might not be that big of a deal. 

If you do decide to reload this ammo, you’ll find that the round uses less powder than a .223 cartridge. This can help add to your savings, but some may still find the process too time-consuming to be worthwhile. 

.300 Whisper vs .300 Blackout

Fingers holding sub sonic round 

The .300 Whisper and .300 AAC Blackout are often compared, not necessarily as two opposing cartridges, but as parent and child. The .300 Whisper is the predecessor to the .300 BLK round, which is arguably more popular. 

Though the .300 Whisper certainly meets a specific demand, the .300 BLK was designed with a specific purpose in mind. It had to meet those requirements as a prerequisite to production. 

300 AAC blackout for suppressed performance

With that said, both the .300 Whisper and the .300 BLK are meant for suppressed performance. This makes it much easier to rely on them in various situations where stealth is called for. (2)

.300 BLK vs. 5.56

300 BLK and 5.56 NATO side by side

The .300 BLK is often compared to the 5.56 NATO to give shooters an idea of what this round is capable of. For starters, the 5.56 is much cheaper to shoot and, in some cases, can be half as much, depending on ammunition choice. 

However, both the 5.56 NATO and the .300 BLK can be used for several scenarios. Many shooters take these cartridges to the range for target shooting or plinking. 

You can also use both types of ammunition for hunting and self-defense. If the round can take down a medium to large animal, a human target certainly qualifies as well. 

Speaking of hunting, 5.56 rounds are more commonly available in rounds suited to precision shooting. That’s not to say that these cartridges aren’t accurate, only that the market for superior ammunition is not as fully developed.

Three different types of bullets lined in rows

When shooting over a longer range greater than 300 yards, the 5.56 wins out every time. It has a much flatter trajectory path and kicks less because the ammunition weighs less. 

Compared to the .300 BLK, the 5.56 also retains greater energy across 300 yards with less bullet drop overall for better terminal ballistics. For long-distance shooting, especially hunting, this distinction is key. 

The 5.56 round is designed to shatter and tumble in a target, whereas the stubbier .300 BLK round transfers force into the target as a projectile. While it might be cheaper to shoot a 5.56 rifle, the rounds also weigh a lot less. 

.300 Blackout vs .308

Three different bullets side by side

Both .300 BLK and .308 ammunition can be shot out of an AR-10 platform. However, the .308 is a much larger round with greater terminal ballistics that pack a wallop. 

Ethical kills are much easier to achieve with a .308 round than a .300 BLK, especially for long-distance shots. If you want to take a bear within 300 yards, most hunters would feel more confident behind a rifle shooting .308 than .300 BLK. 

Three cartridges and their bullets

Ultimately, a .308 bullet is a larger round and has more energy and thus greater penetrating power to hit targets. In addition, a .308 takes longer to reach its full potential, but it does so with greater results and a higher ballistic coefficient. 

.300 Blackout vs .223

Two bullets in hands

The .223 Remington cartridge is another common comparison for .300 BLK rounds. Just like the 5.56, however, the .223 requires nearly double the length of the barrel compared to a .300 BLK to reach maximum potential. 

Though the .300 BLK might win the sprint, it certainly lacks momentum in the long run. Over longer distances, the .223 round drops less than a .300 BLK, losing less energy as well. 

What are the Advantages of the .300 Blackout?

The .300 BLK was manufactured for a purpose, which it does well. If you’re shooting longer ranges, a different cartridge will give you a better result, but in close proximity, the .300 BLK performs.

CQB: Close Quarter Battles

A shorter barrel length goes a long way when fighting in close quarters. With a .300 BLK, you won’t have to worry about sticking the muzzle end out further than necessary to clear a room. 

Minimize Recoil and Maximize Control

Rounds in a gun magazine 

Rounds like the 5.56 NATO and .223 Remington require longer barrel lengths to maximize the powder charge and send projectiles out at high velocity. However, bolt-action rifles chambered in .300 BLK don’t need barrel length to propel even sub-sonic rounds. 

The ability to shoot a subsonic round, even at a fast twist rate, puts the .300 BLK a step ahead. 

300 Blackout Facilitates Versatility, Efficiency & Resourcefulness

You don’t have to replace your lower receiver if switching to Blackout. Simply place the new upper receiver on your 5.56 lower receiver, and you’re ready to go. 

The .300 BLK shines when it comes to twist rate to work reliably in several scenarios. It’s your best bet if you’re looking to maximize terminal ballistics at a lower velocity. 

What Are The Limitations of a .300 Blackout?

Many bullets scattered on black surface

It’s hard to argue that the .300 BLK doesn’t meet the challenges brought before it as a round. With that said, however, shooting a .300 BLK isn’t always the best choice. 

So what is a 300 blackout round’s limitations?

Bullet Drop

Fast-burning powder and a short barrel may propel this projectile faster out of the muzzle, but those rewards diminish once external factors begin working on the round. Specifically, .300 BLK rifle rounds suffer from massive bullet drop beyond 250-300 yards. 

The .300 BLK round is an aerodynamic cartridge. However, the bulk of the ammunition holds it back from reaching its full potential and eventually catches up to it when it comes to terminal ballistics. 

We’ve compared the .300 BLK to the 5.56, but the difference is clear in terms of bullet drop. Where a 5.56 continues its fairly level flight, the .300 BLK drops at a rate of nearly a foot over 300 yards. 


Hands loading a gun magazine

With anything new to the market, price is not necessarily budget-friendly. However, reloading can help you minimize those costs, if you have the time and inclination. 

So what is a 300 blackout round’s typically cost?

When it comes to ammo prices, 5.56 and .223 ammunition win out over .300 BLK. You’ll pay almost twice as much for .300 BLK as you would for 5.56 rounds. 

That said, reloading .300 BLK can save you money and doesn’t require as much powder. However, you’ll need to have spent .300 BLK rounds in abundance or spent 5.56 rounds to cut down if you prefer. 

Home Defense

Identical rifle rounds with black background

The .300 BLK performs well in close-quarters combat, which is something we’ve established already. However, that better performance comes with a few caveats, specifically when it comes to home defense. 

Though the round doesn’t perform well over 300 yards, it almost performs too well in close quarters. You’re responsible for the round as soon as it leaves the muzzle, and with the .300 BLK, that’s a large responsibility. 

A .300 BLK round is sure to go through the threat you face. However, it’s also sure to go through that threat and penetrate barriers until it dumps energy. 

Black gun and ammo on a surface

Therefore, many experts recommend another caliber if you live close to your neighbor. Don’t risk a scary situation turning into a deadly one for an innocent victim if you can make the choice. 

With that said, if you live on acreage and need to protect against bears and other large predators, a .300 BLK might be the one thing that saves your life. It’s all a matter of perspective. 

For more see our posts on what are black tip bullets and can you shoot 300 blackout in 300 ham’r?

Frequently Asked Questions 

300 AAC blackout and 7.62 held in fingers

What’s so special about 300 Blackout?

The Blackout cartridge is so special because it’s a more versatile cartridge that allows for suppressed use and a shorter barrel length. It can shoot both super- and subsonic loads and is compatible with M4-style magazines.

What’s the difference between 5.56 and 300 Blackout?

There are many differences between the 5.56 and the Blackout. A 5.56 round retains more energy across a longer distance than the .300 BLK. 

Additionally, recoil is more manageable with a 5.56 round than with a .300 BLK, and ammunition is often much cheaper for 5.56, too.

What is a 300 Blackout compared to?

Black stencil drawing of bullets

A Blackout is often compared to cartridges such as the .223 Remington, 5.56 NATO, .308, and .300 Whisper. These are common cartridges most shooters are familiar with, with the .300 Whisper fulfilling the role of inspiration for the .300 BLK. 

Is a .300 Blackout more powerful than a 308?

No, a Blackout is not more powerful than a .308. The .308 brings a much higher foot-pound energy rating than the .300 BLK.

How far is a .300 Blackout lethal? 

The Blackout is lethal to about 250 yards or so, depending on conditions and the target. Over 300 yards, the .300 BLK cartridge begins to lose altitude at an increasing rate. 

Which is better: 7.62 or .300 Blackout? 

Many shooters consider the 300 Blackout cartridge to be superior to the 7.62. The .300 BLK has been optimized, while the 7.62 is an older cartridge designed during World War II. 

Bottom of two rounds in fingers


  1. Military Wiki, .300 AAC Blackout. Retrieved from https://military-history.fandom.com/wiki/.300_AAC_Blackout
  2. American Rifleman, Shades of Grey: .300 Whisper & .300 AAC Blackout. Retrieved from https://www.americanrifleman.org/articles/2012/11/5/shades-of-gray-300-whisper-300-aac-blackout/

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