Is a subsonic hollow point round available in .223”? (Dumb question I suppose - I’m on the front end of this and just haven’t looked. Easier to ask?) Seems like anything off std. would be pricey and hard to get.
The only animal I ever shot (some years back) with the .223 was a good size raccoon. Cartridge — I don’t recall EXACTLY, but, pretty std. The round went clean through, essentially body-lengthwise not including the head. I definitely want less penetration than that. Less noise too, preferably. Could get a silencer, maybe, but may not be legal in my state - would have to check.
If your rifle will handle 5.56, the 55 grain FMJ bullets (M193) do not over penetrate at ranges under ~ 100 yards. At higher velocities the bullets will tumble when they encounter a medium with water-like density. The bullet breaks into fragments, creates devastating wounds, and frequently does not even exit. .223 is loaded to lower pressures, with lower velocities, and can over penetrate. At longer ranges the 5.56 does not tumble in flesh and can over penetrate.
Kyle demonstrated this quite clearly for us. None of his hits over penetrated, even when he hit that one guy in the right bicep. The bullet fragmented and destroyed the entire muscle. If it had gone straight through there would not have been nearly that much damage.
Do not use the lower velocity M855 round (63 grain). This round is both lower velocity and has a steel penetrator which will lead to the over penetration you want to avoid.