I’ll be the first to admit, I started exploring the 300 Blackout round because, well, we’ve had a LOT of people come into the shop asking about it.
Sure, my gunsmith/Marine husband knew EVERYTHING about it…but I sounded like a kindergartener when I attempted to answer any questions.
Not one to enjoy feeling like a fool, I decided to figure out why this caliber was becoming more and more popular…and boy, was I shocked at the results!
For starters, the 300 Blackout round is yet another round based on the 30-caliber cartridge. Yet ANOTHER 30-caliber based round? Why in the world is this one any different? Are we getting into a “my 45ACP is better than your 40S&W” debate???
Of course, then I find out that there ISN’T just a “300” caliber. Oh no! There’s:
From Wikipedia: The 300 AAC Blackout plastic tipped, left, compared to 300 AAC BLACKOUT 125 match, 300 AAC BLACKOUT 220 subsonic, 5.56x45mm, and 7.62×39mm.
- 300 AAC
- 300 Whisper
- 300-221
- 300 Fireball
With so many variations, how can you know what ammo to get? In fact, why would you get a 300 Blackout in the first place? Let me give you a little background, then share some of the differences in the types of ammo.
For starters, yes – this is yet another variation on the 5.56. And for that, one would think that there’d be no NEED for another 5.56-type cartridge. But truthfully, that’s like comparing the Judd sisters. One is obviously different from the other. 
Originally, the military needed a cartridge similar to the 5.56 NATO, that could match the ballistics of the 7.62x39mm for knock-down power, but one that had better performance for sound and suppressed fire.
In short – something that could knock down a wall without the whole neighborhood knowing.
Attempts were made to match the 7.62×39 for an AR-15/M4 platform, but too many modifications had to be made.
Which brings me to one of the best selling points for the 300 Blackout:
Granted, we’re not talking about the firearms, but rather the ammunition, but here’s one MAJOR plus to the 300 BLK: the ONLY thing you’d need to change on your AR? The barrel.
EVERYTHING else can stay the same! Even the magazines!
So, if you’ve got a 5.56 AR and know how to swap out the barrels, you’re literally one step away from having a 300 BLK. Cost to entry is definitely a PLUS for this caliber! That’s what I call easy-modification!
On the not-so-great side is the cost of ammo. We can get 300 BLK ammo…but it ain’t cheap. Think about $1.40/round. So reloading education is going to be a MUST.
Most of the variations on the 300 Blackout mentioned earlier (300-221, 300 Whisper, and 300 Fireball, notably) weren’t standardized and therefore caution must be given if you’re looking at these calibers for your 300 Blackout firearm.
However, it should be noted that Hornady makes there 300 Whisper to 300 Blackout specs, so they state you CAN fire the Whisper ammo in your Blackout AR.
So – with ammo at a premium price yet cost to entry being so cheap – when/why/under what circumstances would you choose a 300 Blackout over say, a 5.56 AR?
From a self-reliance standpoint (meaning that I am forced to defend my property/family against a less-than-friendly foe), I wouldn’t want to attract a lot of attention to the fact that a gun fight may potentially be taking place on the premises. Sure, you’re still firing an AR so it’s not like it sounds like air being released from a balloon when you shoot it – but it’s DEFINITELY easier to suppress…especially when you have the right equipment to do so.
From a hunter standpoint, it’d be great to take down a 10-point buck and NOT scare away every other buck within earshot. Especially when you can take him down at 200 yards (with supersonic ammo)! Excellent for hog hunting as well.
From a storage standpoint, I’d much rather have a barrel in my safe than an entire separate AR. Being able to swap out a 5.56 barrel for a 300 BLK barrel makes firearm storage in your gun safe a much easier problem to solve (unless your safe is like ours in which case…you ALWAYS find another gun to take up the slack!)
Suggestions:
– If shooting a 300 Blackout, use different colored magazines, or clearly label them so that you don’t accidentally shoot your 300BLK through your 5.56 rifle (that would be a bad day, indeed).
– It’s often a good idea to have an H-2 buffer (since it’s heavier, it’ll slow the cycling of the carrier as it’s being blown back). However, a standard H buffer will work fine in a pinch.
– You can have an outstanding gun. But if the barrel is a piece of crap, you have an outstanding piece of crap. Fighting Sheep Dog uses Alexander Arms for all of our custom 300 AAC Blackout builds. If you’d like a quote or want to learn more about our custom AR builds, check out the information here.
– Save your brass! Look into reloading your ammo. Averaging about $1.40/round t’s a LOT cheaper to reload than to buy new. However, given the
Bottom line, after doing the research, for both self-reliant needs for hunting AND defense outside of my home, I will be building a 300 AAC Blackout to keep in my arsenal.