Every time I see someone ask about non-5.56 calibers on the AR-15 platform, there’s a legion of fanboys who start proclaiming that .300 AAC (aka, .300 BLK or Blackout or whatever) is the way to go. Let’s take a look at its capabilities:

• Subsonic .300AAC? All the ballistics and energy of .45ACP. Somewhat better penetration due to bullet profile, but I don’t get the hype at all. We’ve spent literally decades declaring PCCs and SMGs dead, and now this is the hotness?
• Supersonic .300AAC? Nearly indistinguishable from 7.62×39 in terms of ballistics, and if you’re OK with .308 bullets in a .311 bore, the bullet selection is the same.

Yes, .300AAC can be a .45 ACP and a 7.62×39 on demand. That’s the best cartridge design of the years 1911 and 1944, all in one gun. That’s not a compelling to me. But, OK… let’s say that is compelling to you. I can use my imagination!

Continue reading I need someone to explain .300 AAC to me; or, better calibers for your AR →