Really? One reason they adopted the .223 is that troops can carry more ammo because it's lighter, of course. But I seem to remember reading, long ago, that the .223 round was also chosen in part because it's more likely to WOUND (see dead vs. wounded stats at any "mass shooting," let alone any combat engagement), and a wounded man will take three enemy out of action, since it takes two guys to haul the casualty back to the aid station.
I wonder how much trouble it would be for someone to put together a "reply" video (shot outdoors, not at a 50-yard indoor range):
"They want to ban the civilian, semi-auto AR-15 because CNN reports it's 'designed to inflict maximum damage.' OK, let's examine these three cartridges: This is the .223 developed in the 1960s and used in an AR-15 (second from right, above, next to the Russian short.)