My kids and grandkids used a 223 with great success on deer and pronghorns. 62 gr, Federal Fusions worked very well. Once they could handle some recoil or elk hunted (243 min. by law for elk here), a 243 or 260 came into the mix. My oldest son was good sized and ended up using a cut down 25-06 the most, but he was the exception. My friend has his young grands use a 22 Hornet, lung shots under 100 yards proved lethal, but it’s too light for my taste.