The .300 Blackout

Gorilla Ammunition .300 BLK ammunition

I have always felt that one of the greatest advantages of America’s Black Rifle is modular construction and the .300 Blackout is a popular option for many reasons. It is simple enough to quickly change the upper to a carbine, long-range rifle, or even a different caliber such as the 6.5 or 6.8 caliber. A carbine with a good trigger action may be fitted with a long barrel for competition use. A home defense rifle may become a hunting rifle. While you may change barrels obtaining a complete upper is by far the simplest and cost effective in the long run.

.223, .300 BLK and .308 Winchester
.223, .300 BLK and .308 Winchester – the .300 BLK is a unique and specialized cartridge.

The .300 Blackout is a popular option for many reasons. First, the conversion works and is reliable. The bugs are worked out, and the rifle will feed function and run with .300 BLK ammunition. The .300 BLK uses AR-15 magazines and the standard 5.56mm bolt carrier assembly.

Ammunition is highly developed. The original intent of the .300 BLK was to offer an effective cartridge for use in suppressed weapons. The heavy weight subsonic loads fulfill that mission superbly. Accuracy is a long suit of the .300 BLK. It isn’t unusual for custom grade rifles to deliver sub MOA groups at a long 100 yards. The question, then, is power not accuracy. The .300 BLK is accurate enough for any use. Reliability is confirmed in credible rifles.

As for power the .300 BLK is comparable to the 7.62 x 39mm. Remember, velocity is often expressed in a short-barrel rifle—not the full-length rifle—I am testing. Also due to the extreme aero dynamics of the bullets used the cartridge outperforms the Soviet cartridge at 200 to 300 yards. However, never mind that, the AK-47 isn’t accurate for long-range use and neither are most 7.62 x 39mm AR-15 uppers. The .300 BLK is NOT an alternative to the .308; these are completely different missions.

The .300 BLK is a pretty exciting option for use in suppressed rifles with short barrels. I do not play with such items, but have friends that do and find them a fascinating study. The .300 BLK is a credible option for entry use and for dispatching lights and guard dogs. The .300 BLK should be the equal of the 5.56mm at short range as far as wound ballistics and considerably superior to the 5.7mm, .30 caliber carbine, 9mm SMG, and the like. However, some of us will use a standard 16-inch barrel conversion for the .300 BLK.

Sig Sauer Elite Performance JHP ammunition
SIG’s Elite Performance JHP offers game taking performance.

Ruger offers a seldom seen Mini 14 variant in .300 BLK as well. My perception of the rifle at first is that this is a specialized caliber. It is ideal for the use it is intended but a far as hunting, I think that a very narrow spectrum of performance, perhaps as a hog gun, is where we are at with the rifle. With this in mind, I decided to test a number of loads using the Rock River upper with the .300 BLK. The scope is a TruGlo illuminated reticle version.

Gorilla Ammunition

This company was founded on the .300 Blackout and offers a number of first class loads. The load I tested was the 125-grain Sierra MatchKing. This is a bullet with excellent accuracy potential. We are dealing with a bullet with much better sectional density than the .30-30 WCF with its 150-grain bullet at 2200 fps so the 125-grain Sierra just may make a comparable deer load given good shot placement. It is lighter than what I like for deer, preferring the .308, but something must be said for low recoil and excellent accuracy. This load breaks 2150 fps average.

Gorilla Ammunition .300 BLK ammunition
Gorilla Ammunition is a strong favorite among .300 BLK shooters.

Hornady American Gunner 125-Grain JHP

At 2200 fps, this load remains controllable. The new American Gunner .300 BLK is available in 50 round boxes which aids in inexpensive (relatively—expense is relative with the .300 BLK) practice. Accuracy is good and the powder burn is clean. Hornady’s quality is evident. Hornady also offers a 110-grain load I was unable to test at this time.

Fiocchi Rifle Shooting Dynamics

This is a relatively heavy bullet at 150 grains. Velocity is 1950 fps. Of the loads tested, this load seemed to give the lowest recoil and also burned clean. Accuracy was excellent, something we were getting used to with the .300 Blackout. This is a good accurate affordable burner load with much to recommend.

PNW Arms

I have used the Sierra MATCHKING 220-grain bullet in the past in the .30-06 rifle with excellent results. These old heavyweights can be quite accurate. The combination looks odd in the short .300 BLK case, but shoots as well as anything at moderate range. At 1050 fps from the 16-inch barrel, this load would be ideal for a suppressed rifle with a short barrel. Velocity would probably drop to about 950 fps in a SBR.

Hornady American Gunner
Hornady offers the American Gunner in affordable 50 round boxes.

The drop was greater than the other bullet weights, but for the intended purpose, personal defense, this is a credible choice. PNW also offers a 147-grain bullet load. This is the same bullet weight used in bulk .308 loads and a good choice for economical practice. Velocity is around 1950 fps on average. This loading also gave a clean powder burn, which seems to be a hallmark of the .300 BLK.

SIG Sauer 120-Grain All Copper HP

SIG may have introduced the best hunting load so far in this interesting caliber. With an all copper HP at 2,250 fps from a 16-inch barrel this loading offers excellent accuracy and predicted effect on target. SIG also offers affordable FMJ training loads.


HPR offers a 220-grain subsonic, 110-grain practice load, and 110-grain hunting load. Ballistic testing with the 110-grain load is impressive. The all copper bullet expands to .50 at a solid 2100 fps. This is an outstanding load that burns clean—a big plus that HPR ammunition always demonstrates.

After firing a modest amount of .300 BLK ammunition, I find a clean burning accurate cartridge with interesting capabilities. It is something of a wonder cartridge with excellent accuracy and low recoil. One thing is certain the loads are first class examples of the maker’s art.

Are you a .300 BLK fan? What is your favorite .300 BLK loading? Share it in the comment section.


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Comments (53)

  1. I wanted an AR platform that I could load a variety of .30 bullet and the 300 BLK is a cheap cartridge conversion with a lot of versatility. I prefer the 125 grain Sierra bullets but have loaded a lot of cheaper 130 grain bullets with good success. I found some 145 gr surplus euro mil surplus and made a great load out of that. I even loaded some USGI AP rounds as an experiment and was able to penetrate 1/4″ cold steel at 25 meters, try that with 7.62×39! My AR pistol in 300 BLK with a 12″ barrel makes a great poor man’s SBR and is effective and fun!

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