I forgot to mention. You might kill a lot of game with those smaller caliber rifles but in most of the eastern US black bears are making a huge comeback and bear attacks are on the rise big time. That's why no 30-30, 7.62 x 39 or .223 is really big enough. If you carry a rifle that will fire a big round it will also fire a smaller round with less power. The 30.06 is the Swiss Army Knife of rifles for that reason. You can buy all kinds of ammo for it including reduced power loads that are good for most anything. And you can reload and have rounds suitable for squirrels and rabbits. Nothing beats a 30.06. It's not even close. You can buy bigger rifles of course but a 30.06 will kill anything in N. America so what's the point?