The ideal for ethical hunting is to put it down and dead as quickly and cleanly as possible.

Unless you are an expert marksman the chances increase for wounding an animal, instead of killing it, with smaller calibers.

In many places the smallest caliber considered sufficient for a reliable kill on larger game animals used to be a .270 or 6.5 mm. They've relaxed that some in some places.

I say if you are good enough go for it. if you aren't an expert or reasonably competent, one of the responsibilities of an ethical hunter is to never let a wounded animal suffer. If you are going to be ethical and use a .223 IMO be prepared to spend many, many hours tracking wounded game through brush, heat, ticks, biting flies or whatever to find that Deer or Hog you wounded. I've walked myself into total exhaustion on more than one occasion tracking a wounded animal.

Going out and shooting up the countryside, wounding animals and letting them run off to die a terrible death isn't hunting, it is thrill killing IMO. And thrill killers give everybody who is into shooting sports and/or hunting a bad name.