[Sea Parrot]

If hollow point or soft point sporting ammo was used, those bullets would upset out to 5-6 hundred yards. Military hard ball ammo is designed specifically not to fragment at any range. (per geneva convention specs. The 5.56 military bullet may tumble inside a soft target like human flesh.

Fragmentation is a bad thing for ammo it one wants penetration, and is normally reserved for varmint hunting.

The 5.56x45 versus a .45 acp is apples and oranges, but both can kill a person dead, as in very dead.

[nerdwithagun]

Many of the military spec 5.56mm WILL frag if it is one of the several cantalured rounds at at least around 26-2800 ft/sec. Fragmentation can work very well again if it is fast enough an how it fragments. Many self defense ammo is advertised to fragment in a fleshy target. I am talking about solid lead and copper here, not pre-fragmented stuff which is sometimes advertised for self defense. Hornady TAP offers .223 “urban” which is a cantalured copper and lead round which they advertise fragmenting in in gel and a “NTX” which is prefragmented and lead free, total fragmentation in the body.