Not suitable for deer, small bullets designed for varmints are designed for rapid expansion on small critters. Would not penetrate far enough to humanely kill a deer. Winchester does make a 64-grain hunting bullet, but with the slow twist of a 222 it would not stabilize and will not be accurate.
Too small for deer? Really? Ever tried it? Never seen a WT make it 25 yards after losing a heart or both lungs.The inuit have been using it for decades on caribou,seal,walrus and even polar bear! And it won't handle a 200lb deer?My dad ran up a string of 11 one shot deer kills never losing one.Handloaded Barnes X bullets or the old 55gr Hornady work flawlessly.Range needs to be kept under 125 yards and you have to be able to shoot.Harold