The world of ever expanding anti terrorism and special operations missions the need for an effective round that works well in close quarters and out to 300 meters is of critical importance. The standard round for years has been the 5.56x45mm in some configuration, BUT is the .300 AAC Blackout really the ultimate CQB round hiding in plain sight? It’s a question being asked more often now.

The .300 AAC Blackout was developed as a joint venture between Remington’s Defense section and Advanced Armament Corp. The round itself was developed off of the older .300 Whisper, a wildcat round that uses the .221 Fireball / .223 Remington cartridge. The .300 Whisper was a project from the early 1990’s and due to a unfortunate series of issues largely fell flat and never had any SAAMIspecifications accepted for standardization of the round. It wasn’t a total loss for the firearms industry though, some people took notice of the ballistics that were achieved.

The point of this article is not to lull you to sleep with the history of the .300 AAC Blackout and its parent case or pervious attempts at developing a similar round. History is important, it gives us a ground work to understand the development of a project. Fast forward to to the 2008-2010 time frame, a lot of the news media and reports coming out of Iraq and Afghanistan were of close quarter contact and house to house raids being the standard operating procedures.

Armed conflict makes people and countries look at their equipment and analyze what works and what doesn’t, its part of survival of the fittest. Anyone who can read ballistics charts, has analytical skill can quickly figure out that a round designed for medium to long range shooting might not be the best tool for room to room fighting. This thought process had to be on the minds of engineers at Remington and Advanced Armament Corp when the .300 AAC Blackout idea was born.


Parent Case: .221 Fireball/.223 Remington

Bullet Diameter: .308″

Case Length: 34.7 mm

Designed Rifling Twist: 1 : 7 Inch

Velocities: Ranging between 1000 Ft / Per second – 2400 Ft/ Per Second depending on load

Magazine Used: All Standard AR15 Magazines

Perviously the “Answer” to the Close Quarter Battle round issue has been either to use a shotgun, a pistol caliber sub machine gun like the Heckler & Kock MP5 or just deal with over penetration. There were other attempts such as designing new rounds for the 5.56 to help mitigate any problems. Physics is a funny thing, fast moving pointy objects seem to really like to punch through soft bodies and come out the other side.

In the last 100 plus years the goal of many ammunition designers has been how do we achieve a blend of lethality and accuracy, without over penetration. How do we deliver accurately deliver the maximum amount of energy in a person or animal and have it stay in the object. The .300 AAC Blackout has taken a page from the playbook of John Moses Browning and made a large bullet move slower and distribute that energy better. All while cleverly utilizing the stock pile of existing .223/5.56mm AR15 magazines and bolt carrier groups. It’s a very appealing prospect to put it mildly.

The .300 AAC Blackout was designed from the start to be used short to medium range from short barreled weapons and with suppressors. It sounds like a Special Forces dream platform to me. There have been unconfirmed rumors that testing the .300 AAC Blackout in the CQBR Mk 18 rifle may begin soon. These are totally unconfirmed, and we are working our contacts and channels to see if this is fact happening or just hopefully wishing. To date only one military unit that I can find has officially accepted the round and that is the Netherland Marine Corps Special Operations Force (NLMARSOF). They have purchased a small amount of these to begin test and evaluation on.

Why Would I want a .300 AAC Blackout ?

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It’s a question I asked myself for a while, I understood the theory behind making an intermediate round and all the science and hopes behind it but I wasn’t interested in another round until….I learned I can use my existing BATFE Papered Short Barrel Rifle as a base to start with. The fact I was able to find a 10.5″ upper for $219 was also a huge plus. Don’t worry if you don’t have a short barrel rifle, many companies make a 16″ barrel in .300 Blackout and they can be found at reasonable prices. Our friends at Armscor were generous to donate a supply of 147 grain FMJ so of course I was up for a little test and evaluation session.

I will for the sake of being brief sum up my experiences that I had with the .300 AAC Blackout that I shot through my brand new Radical Firearms 10.5 ” upper. I only shot 300 rounds of ammo for my first test session with my standard Mil Spec AR15 bolt carrier and experienced zero malfunctions. I used a mix of Surefire, C Products, Lancer and Bravo Company magazines and the .300 AAC Blackout fed into and out of the magazines with zero issues. I also used the MagLula loading tool with no issues.

Actually shooting the rifle I only went to 100 yards, but the round is designed to have an effective range of 460 Meters (503 Yards) and that is a lot farther than I have the skill to utilize. The felt recoil of the .300 AAC from my SBR was actually pleasant to me. It wasn’t as harsh on my twice rebuilt shoulder as other .30 caliber rifles that I have experienced. While I know 100 yards isn’t some magical standard for accuracy but once I dialed in the Trijicon MRO it was putting rounds consistently where I wanted them, have I said how much fun this caliber is to shoot?

Drink the Koolaid ?

Should you as I put it “Drink the Koolaid” and try the .300 AAC Blackout ? If you are an AR15 owner and don’t have a .30 caliber semi automatic rifle then I say why not do it ? Wether or not this round ever gets accepted into the military arsenal and issued to to troops is not the point. The point is using this round essential means you get to use your existing AR15 as two guns in one. Worst case scenario you find you don’t like it you can always just sell the upper and recoup your loss.

There are people who reading this are screaming at their computer and telling me to go buy an M1A, FN SCAR , or an FAL or some other .308 rifle if I want .30 caliber. Or they will say that .300 AAC is too expensive to shoot. It took me all of five minutes on the internet to debunk that and find .300 AAC with full metal jacket 110 grain bullets for between $11-13 a box of 20. That is on par with .308 FMJ rounds or even a bit less depending on which online source you are using.

.300 AAC Blackout is also being produced by more manufacturers every six months it seems someone is releasing a new variety, which drives down the cost of other brands in theory. The development of the round has seen the release of ammunition with bullet weights from 78 grains all the way to 220 grain sub sonic. Full metal jacket, hollow points and ballistic tips of all weights are available from makers such as Armscor, Remington , Sig Sauer, Hornady, Fiocchi.

If you are currently shooting the .300 AAC Blackout drop us a line in the comments section and let us know, some pictures if you want to play show and tell. We would love to see what works and doesn’t for this platform. I’m just getting into it and still considering optics since my MRO goes back on the .223 rifle. Thanks for stopping by.




This article is courtesy of The Loadout Room.