It’s a conflict as old as most of us reading: The AK-47 vs the AR 15. As storied, staunchly debated and stubbornly bickered as the comparison between these two rifles is, the rounds they shoot are surprisingly similar. In fact, Kevin Brittingham, the founder of AAC and the mastermind behind the 300 Blackout put it this way, “The muzzle energy had to equal or exceed the AK-47, and it had to be a .30-caliber projectile.”
So there you have it! 300 Blackout and 7.62x39 are so much alike that it’s really a crapshoot, right? Absolutely not. While the rounds appear similar at face value (and by looks), and while both maintain similar ballistic coefficients (depending on grain and load), the two rounds have different applications that only occasionally cross paths. Before we get into the breakdown, let’s follow our scientific formula – knowledge is power, after all – and compare these two rounds’ numbers, shall we? Because there are so many 7.62x39 loads, we’ll use the Gold Standard, if you will, a classic 123-grainer.
300 Blackout and 7.62x39 by The Numbers
- Weight (average): 123 grains
- Velocity (average): 2,430 ft/s
- Energy (average): 1,600 lb.-ft.
300 AAC Blackout:
- Weight (average): Supersonic, 125 grain, Subsonic, 220 grains
- Velocity (average): Supersonic, 2,215 ft/s, Subsonic, 1,010 ft/s
- Energy (average): Supersonic, 1,350 lb.-ft., Subsonic, 500 lb.-ft.
A 7.62x39 AR 15, Really?
Sounds taboo, we know – but it’s a real thing. And when you think about it, throwing this venerable Ruskie round into the American black rifle isn’t all that much of a bad idea, when you consider the application and purpose of the 7.62x39. Although not labelled the most accurate intermediate rifle round ever made, the 7.62x39 offers respectable ballistics when loaded properly. The Ruskie round’s effective range is 400 yards, though most say that 200 yards is the furthest good shot groups will be found. Compared to supersonic 300 Blackout’s 460 rounds, we’re not seeing big difference.
If we look at sheer force and velocity, 7.62x39 wins again, traveling around 200 feet per second faster with 250 lb.-ft. more energy at the business end. So the Ruskie round’s better, right? Wrong. 300 Blackout outmatches 7.62x39 in ballistic coefficients at nearly every distance. It’s just a more accurate round, and how much is a heavier-hitting round that misses actually worth? Zilch.
The 7.62x39 is an all-around decent cartridge for just about whatever application you put it through. It’ll hit decent shot groups, it’ll hit at decent distances, it provides just-okay ballistic coefficients, and it’s cheap. It really is a plinker, through and through. Some folks make them subsonic for suppression, but the ballistic data is so poor compared to 300 Blackout that, ironically, it’s not even worth comparing.
Why the 300 Blackout AR 15 is Better
By the very nature and modernism of its dual purpose design, 300 Blackout is simply an all-around good cartridge for any AR 15 rifle or AR 15 pistol. It’s just better than 7.62x39’s reputation as a “all-purpose” round, to be sure. Want to hit out to 500 yards with a decent ballistic coefficient? Slap a mag full of 125-grainers and start shooting.
Want to go suppressed for the nighttime hunt? Swap that mag for some 220-grainer, thread on that can to your muzzle, and watch your lane. Suppressed, 300 Blackout packs more oomph and goes further than most sub guns and pistol ARs. Supersonic, the 300 Blackout hits with accuracy comparable to 5.56, but in a heavier, bigger round. It’s the only round that can manage both jobs without any Gunsmithing and without swapping parts on your rifle – that alone is worth its weight in gold. Compared to 7.62x39? It does the Russian’s job faster, better, and with more precision. Sorry, Soviets. Better luck next war.DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. We are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.