.300 Blackout vs 5.56 NATO
When it comes to rifle cartridges, one could get lost in all of the options there are to choose from. For this article though, we will be focusing on two very popular, yet very different calibers used for Armalite 15 patterned rifles: .300 Blackout and 5.56 NATO.
The 5.56x45mm NATO round has been the gold standard AR-15 cartridge for well over 60 years. Not only has it been the main FMJ ammo round issued to our military, but it has also seen combat on five continents in the hands of the U.S. Military. However, there is another round that shooters wanted more out of for their AR platform.
They wanted the ability to shoot a 30-caliber bullet without switching over to the AR-10. Introducing the one and only .300 AAC Blackout. This is the perfect combination of the 7.62x39mm terminal ballistics with the modularity of the AR platform. This is an effective and attractive combination that many shooters have declared superior to the 5.56 NATO round. So, which round is better then?
While both are used in similar applications such as hunting, training, and self-defense, there are some key differences between the two that really set these rounds apart. Join us as we compare the new kid in town, the .300 AAC Blackout, to the tried and true 5.56mm NATO in this legendary shootout.
Why Buy .300 Blackout?
The development of the .300 Blackout (designated 300 BLK by SAAMI) and known as the .300 AAC (Advanced Armament Corporation) round began in 2010 when Robert Silvers of Advanced Armament Corporation was approached by a member of the U.S. military special operations community with a problem. This was a problem that Silvers was eager to solve.
With the adoption of the 5.56 NATO round for the M4 carbine, U.S. troops were having to use the round for both long-range and close-range combat. Some military units were not satisfied with the stopping power the 5.56 round produced. They wanted something with a little more "oomph." They also had additional requirements:
- The round needed to fit into a standard STANAG AR-pattern magazine and maintain a 30-round capacity.
- It had to shoot 30-caliber bullets and mimic the ballistic performance of the 7.62x39mm Soviet round.
- The cartridge case head had to match the 5.56 NATO round so no bolt change was required.
With these challenges presented, Silvers began work on a new cartridge. He found the 300 Whisper wildcat cartridge to be the best starting point but it lacked SAAMI standardization and couldn’t be mass-produced. As AAC was a SAAMI company, Silvers modified the design, and in 2011, the 300 AAC Blackout was officially approved by SAAMI.
The .300 Blackout typically uses heavier projectiles than the 5.56 NATO, with bullet weights ranging from 110 to 220 grains. It supports both subsonic and supersonic loads, making it versatile for various applications. The muzzle velocity and energy of a typical supersonic .300 Blackout round (Barnaul 145 grain .300 Blackout in this example) is 1985 fps and 1268 ft-lbs, respectively, with a ballistic coefficient of .366. The round is optimized for full powder burn from a 9" short barrel rifle (SBR).
Need bulk .300 Blackout ammo? Here at True Shot, we have a great variety of .300 AAC Blackout ammunition options from different manufacturers.
5.56 NATO
The 5.56x45mm NATO round was originally developed for military use in the M16 rifle. After the Korean War, the U.S. Military began designing a new rifle cartridge. In 1954, the 7.62x51mm NATO (.308 Winchester) was adopted, but early engagements in Vietnam revealed the need for a lighter, intermediate cartridge. This led to the .223 Remington, which became the M193 cartridge. In 1980, Belgian manufacturer FN Herstal introduced the SS109 5.56x45mm cartridge (U.S. designation M855), which became the new NATO standard.
The 5.56 NATO round features a .223-inch projectile and is designed for supersonic performance. Its high velocity and flat trajectory make it effective at longer ranges. Typical bullet weights range from 55 to 77 grains. A standard 55-grain 5.56 NATO round (PPU 5.56 55 grain M193) delivers a muzzle velocity of 3240 fps and 1282 ft-lbs of energy, with a ballistic coefficient of .248.
Need bulk 5.56 ammo? Here at True Shot, we have a great variety of 5.56x45mm ammunition options from different manufacturers.
What Is the Difference Between .300 Blackout and 5.56?
One of the main advantages of the .300 Blackout is its compatibility with existing AR-15 rifles. It can be used in a 5.56 NATO platform by simply changing the barrel. It’s an excellent option for hunters and shooters seeking effective short- to medium-range performance with low recoil. It is often used for hunting deer, varmints, predators, and hogs, but always check local regulations. Many also use it for home defense with subsonic rounds and suppressors, reducing noise and overpenetration risk.
The 5.56 NATO, however, excels where .300 Blackout falls short. Its high velocity makes it ideal for long-range accuracy and consistency. With minimal recoil, it’s easy to control and has been trusted by the U.S. Military and law enforcement worldwide for decades. It’s also more affordable and widely available. For hunting, the 5.56 is best suited for varmints, predators, and smaller game. In contrast, the .300 Blackout’s heavier bullet performs better at short ranges but loses velocity quickly beyond 100 yards. The 5.56’s flatter trajectory makes it superior for distance shooting but more prone to overpenetration indoors.
.300 Blackout & 5.56 Price
The .300 Blackout round is generally more expensive than the 5.56 NATO due to lower production volume and availability. For example, a 20-round box of Barnaul 145 grain .300 Blackout costs about $13.49 (67 cents per round), while a comparable 20-round box of PPU 5.56 NATO (55 grain M193) is around $9.99 (50 cents per round).
.300 Blackout vs 5.56: What's Best for You?
The .300 AAC Blackout is a hard-hitting 30-caliber upgrade for the AR platform, mimicking the 7.62x39’s ballistics with added flexibility. The ability to switch between supersonic and subsonic loads with only a magazine change makes it versatile and unique.
The 5.56x45mm NATO round remains a proven and cost-effective option. Its long-range accuracy, reliability, and widespread availability make it ideal for training, defense, and general use. While the .300 Blackout excels in short-range versatility, the 5.56 remains the standard for range, affordability, and precision.
Need bulk ammo? At True Shot Ammo, we have 5.56 ammo and .300 Blackout ammo available to purchase. Visit trueshotammo.com, call us at (888) 736-6587, or email sales@trueshotammo.com for more rifle ammo options.
