I'd go with my .243 Ackley Improved.
I'd shoot any animal in North America with it, certainly up to black bear and elk, without a second thought. I'm confident that an 80gr Barnes TTSX leaving the muzzle at 3,550fps and routinely exhibiting 3+ feet of penetration would handle anything I'll ever need to shoot. On the other end, a 55gr varmint bullet at 4,100fps would be quite... dramatic... on anything small(ish).
Still happily answering to the call-sign Peetza.
You do not HAVE a soul. You ARE a soul. You HAVE a body.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.