This made me think of a P.O. Ackley quote about Elmer Keith.taking into account all circumstances that could arise,i believe that elk rifles start at a 30 caliber magnum.
"I don’t think Elmer Keith would be caught dead hunting with anything smaller than a .300 Magnum. And he used to tell me that was about minimum for deer. For other stuff he starts up from there. Of course, if you figured things proportionately, guns for moose or bear; the gun would probably be at least 37mm."