The .300 Blackout is definitely a Kool-Aid kind of cartridge—you either love it or you don’t. Nobody I know has a Homer Simpson-like “meh” attitude about it.
Me, I’m on the dark side. I have yet to wholeheartedly buy into Blackout Fever. Why? Because it’s not particularly good as distances stretch past a couple hundred yards, and when I stuff a cartridge into a rifle, I want it to act, well, rifle-like. Until recently, I considered the .300 Blackout a very non-versatile cartridge.
A friend of mine, a ballistician at Barnes Bullets, made a comment that recently caused me to grudgingly crack the door and consider the Blackout more objectively: “It’s the best carbine cartridge out there for combat.”
A lifetime of gun technicana and a recent tour to Afghanistan backed his comment up. “What about long range,” I prodded.
He looked at me as if I was an idiot. (Could be he’s right.) “That’s what designated marksman and snipers are for.”
OK, in a team scenario, that made a lot of sense. The discussion continued. “What about for individual use? It’s not very capable as distances stretch.”
My buddy politely made the point that neither are most shooters, and closed his argument with the undeniable statement that within the ranges at which most conflict occurs, the .300 Blackout has considerably more impact authority than the 5.56mm.
My bias wasn’t exactly squelched, but it was cracked, and other considerations came flooding in. Finally, I had to admit perhaps, after all, the .300 Blackout is a very versatile cartridge, especially if you handload for it. Here are a few prime reasons why.
(1) Cut the .223 cases off just below the shoulder with a Dremel tool, lathe or however you want to do it.
(2) Run the cut-off cases into a standard .300 Blackout sizing die. The die will form the new neck and shoulder.
(3) Trim the formed cases to length (1.368 inches). All that’s left is to knock the burrs off of the inside and outside of the neck and load ’em up!
To get started, you’ll need to fill out the appropriate paperwork, order a .30-caliber suppressor and then twiddle your thumbs while the bureaucrats work out the red tape. You can make the most of the time waiting by loading up a bunch of rounds with 220-grain Sierra MatchKings or 208-grain Hornady A-Max bullets. Better practice giggling so that your stomach lining is conditioned to take it when you finally get the suppressor and turn loose those lovely oversize bullets.
Today’s premium .223 and 5.56mm loads get a lot of mileage out of the cartridge, but the .300 Blackout is designed to shoot 125-grain projectiles with energy approaching and even equaling that of the legendary AK-47 cartridge: the 7.63x39mm. The very best .223 loads offer about 1,400 foot-pounds of energy; the .300 Blackout averages that or better and offers the benefits of larger diameter and increased mass—to the tune of about double that of the heaviest .223 projectiles that will feed reliably through a magazine.
Since it’s based on standard 5.56mm and .221 Fireball cases, the Blackout has the same overall length as a 5.56mm cartridge. Also, the critical contours of the bullet’s ogive typically contact the feed ramp of an AR-15 in similar fashion to the 5.56mm, allowing it to cycle beautifully with standard M16 magazines. As a nice little bonus, it also uses the same bolt, gas system—same everything but the barrel. Turning your worn 5.56mm AR-15 into a .300 Blackout is about as easy as a caliber conversion can be.