What can't you kill with a .30-06 within 200-300 yards? particularly in North America?
110-220gr bullets.

I would bet if you grew up with a .30-06, you love it, or it's sentimental, and no reason to get rid of it.

Also .30+ Magnums aside, what would you want to use on something big, heavy, or even dangerous?

I would bet as many of us age or get sick of being kicked around by magnums, going from a .300mag down to a .30-06 would be a small step down for much less kick.

I bet it's in the top 10 selling cartridges in America until everyone is shooting lazer guns... and probably even then it'll still be in the top 10.

maybe a better question is why shouldn't it be in the top 10?

I wonder how many people in this country have been passed down a rifle, and the only rifle they own is their dad's or grandpa's .30-06? they buy a box of rounds and shoot it once every year or 2 at the range.