It looks like the .223 is NOT high caliber, but it IS high velocity.
The high velocity gun shot wounds have variable rates of survival, primarily predicated upon the site of trauma. Obviously, if a major artery or vessel is severed, you're dead. On the other hand, I recall seeing multiple patients as a lowly medical student and watching the heroic trauma surgeons saving life. I remember one patient where the intern was showing me how to clean bullet wounds and attempt to identify the location of the round in the body. The patient was talking to us and we stuck a long cotton tipped swab into his neck wound... As this 4 inch long swab went in one end, the intern realized...it kept on going through his neck... right through the other side! It was cool... the patient lived too (too bad he was just another inner city gang banger type).
One pretty hot varminter load on a .223 with a 52 gr Sierra bullet is about 20 grains of IMR 4198. Compare that to the .308 Win pushing a 110 gr Hornady with 38 grains of the same powder (also a hot load). About 3,000 fps. I use the 165 gr BT match bullets in .308 mostly though, and powder's correspondingly less.
I'll acknowledge that it's a fast bullet, but lightweight. I don't care for it. . . would prefer .25'06 for varminting myself, but it does tend to eat barrels.
Of course, reloaders are the most opinionated people on earth . . . ;-)
Yes it is, but the DoD defines it as an "inermediate power" cartridge, not a "high power" one like the 7.62 NATO (near clone of .308) or the older (still military) 30-06, which itself happens to be the most common round for hunting in the US, (other than the .22 long rifle that is).