Ah ha!
Thank ya very much
I'm assuming the damage would only worsen if the round was a hollow point, yeah?
I haven't seen anything that would indicate that - however logic dictates that this would be so.
the downside to Fackler's research (the bits of it I have read- it's extensive as hell- so if he ever experimented heavily with expanding 5.56, I haven't come across it yet. I've seen some commentary from him on expanding 5.56 -but no wound diagrams or extensive narrative on it.) is it primarily focuses on military rifle and pistol (FMJ) or law enforcement expanding pistol calibers and bullet construction - and predates the now prolific usage of the .223/5.56 in a law enforcement setting where HP/expanding ammo would be commonplace. (back before the late 90s the rage in LE for long guns... besides the venerable 12 gauge shotgun - was for pistol caliber carbines like the Colt SMG or HK MP-5.
As far as I know - the only HP bullets that are approved for use by the US military are the Open Tip Match (OTM) bullet as loaded in the M118LR, MK316 mod 0 and the M852. all of which are .30 cal
however a safe assumption is an expanding 5.56 cruising at the velocities the round is known for would be a real nasty customer, and probably would be more effective beyond 200m than FMJ of equal grain
I do have a few boxes of 45 grain Winchester Varmint HP .223, which I keep for home defense based on some interesting stuff I've come across on the net about how lightly constructed high velocity .223 has a tendency to self destruct after hitting 2-4 layers of drywall and turn into lead and copper confetti that may wound - but probably not kill. counter intuitive, yes - but the experiments I've seen seem to be well run and free of any glaring mistakes in method. From personal experience - 9mm and .45ACP can and will punch through most of a house from the street (I did an inspection on an apartment that had been hosed in a drive by - there were bullet holes that went from the facade of the building all the way through the home and exited out the back wall. the police said they found a ****load of 9x19mm, .380, and 45 casings in the street, and the rounds that got lodged in the walls were of those two calibers) this was around the time I started to re think my HD firearm choice which was a 9x19mm pistol.
however the expense for such premium .223 rounds for me is pretty prohibitive - at least in any kind of bulk. and the likely hood of having to defend myself beyond 200m is very very low. (and if it ever came to that - my 270 bolt gun flinging a 130 grain Hornady Superformance Ballistic tip or even a Winchester whitebox powerpoint would be a better way to deal with such things IMHO)