.300 Whisper? .300/.221 Fireball? .300 AAC Blackout?

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I wasn't going to ask what the heck is the deal but I found this link.... for anyone interested this article is a good read and clears it up.
https://www.americanrifleman.org/articles/2012/11/5/shades-of-gray-300-whisper-300-aac-blackout/