An AR-15 is used to 223 full metal jacket bullets at young deer. If you are an experience hunter, then you seek the pro shot known as its gold name “the whole in one”: this type of bullet goes through the animal’s, out the other side without hitting bone to slow it down then hits the female deer or doe a few meters behind it, thus killing to deer with one one bullet. The full metal jacket was popular in the Vietnam war for about the same purpose. It was known there as the “peace-lovers” bullet because it was thought it would end the war sooner.