Anyone ever use subsonic .223 for whitetail? I’m assuming the only reliable shot would be a head shot? Well, reliable as long as you are a good enough shot/limiting your range enough to reliably make the shot….
OR is there a .223 bullet out there specifically designed to expand at subsonic velocities?
No, and here's why:
Some years back I found a buck fawn someone had attempted to poach with a .22lr. Deer was acting really weird, really weak, couldn't run, could barely stand, and I shot it in the head with my CCW at the time. At contact distance. Muzzle touching head.
Later when I skinned it (this was during season, we are allowed to kill multiple antlerless per day, I notified the local CO and he said just check it in as normal) I found a .22lr in its lungs. It was dying, from a tension pneumothorax. It wasn't pretty to watch happen. I relayed this info to the CO, for whatever that was worth.
(In fairness, the bullet had went into the back part of one lung and the very far rear tip of the other)
But here's the thing: That happened with a .22lr that probably was shooting a 40 grain bullet at near subsonic speeds, or possibly slightly supersonic. I think the same bullet in the heart would have likely killed it within seconds, but obviously there's zero margin for error there. As it is, a heavier .22 bullet at similar speed might have penetrated further, and might have put a slightly deeper hole through both lungs, but as it was, the hole that was there, wasn't enough to produce the desired effect. And a bullet that small that would have expanded, might have left a bigger hole in one lung but lacked the momentum needed to make any hole at all in the second lung.
I have killed deer with larger bore stuff at handgun speeds (.45 colt) and with zero expansion a typical .45' flat point will make a wound that causes rapid drop in BP and the resultant shock/death. A .22 caliber bullet with any sort of pointy point may not. It's just too easy to make a wound that is fatal but not rapidly so.
I shoot varmints around the farm with .22lr subs all the time, up to the size of coyotes/bobcats (trapped). A CCI SV in the noggin from 30 feet away will kill them faster than I can cycle the action and walk 30' to them. When I approach a trapped animal they usually get excited/agitated for a few seconds then stop to stare at me. I wait for the stop/stare and brain them.
I don't know *exactly* where the line is between a .22/77+ grain bullet at perhaps 1100'MV (that will hold 1000'+ for a long distance as velocity decay happens fairly slowly at subsonic speeds) and that same 22/77+ at the typical 1600-1800' impact speeds that most people strive for. But the thing is,
I don't want to know, and I don't think you can really find that line without risking a few inhumane kills.
I personally do not think it is ethical to shoot a game animal with any .22 caliber subsonic projectile that I am aware of. The margin for error is just too small.
If I wanted to quietly kill things with subs I would buy a .350 Legend and shoot the 255 factory loads. I've shot those in my kids' single shot. I've also shot subsonic 358-200 rnfp over ~4 grains of 700-x. Even then I'd consider that to be the lower end floor of what would kill quickly. Handgun hunters 40-50 years ago used to argue over whether the .357 Magnum was enough. I think it is, up close, but I also think it's about the floor, and the .350 Legend with subs is about in that same ballpark.
YMMV, I'm no expert, but I hated watching that buck fawn suffer.
In the last decade(?) I think the shooting world has learned that the floor for ethical killing is much lower than we thought, but there is still a floor. I'd consider any subsonic .22 to be below it.
