DucofDeath3
Although one might say "live and let live and take all things in moderation."

This principle does not hold true when hunting truly big game. Yes, a .243 and .223 can kill white tale and turkey well, I too have used both. However the simple fact is that small 55 to 100 grain bullet no mater the make sent out a velocities at or near 3000fps will not deliver enough "shock" or penetration to disable much less outright kill a large game. In North America moose, caribou, and brown bear are simply too big and tough to be taken with a .20 caliber weapon. Elk and mule dear could be taken as you describe however your effective range would be so greatly reduced you would almost never get a shot off.
It is true that some hunter will use bore size to compensate for a great many things, not the least of which is marksmanship.

They allow the gun to do what they can not! Not to understate, shouting skills, a hunter mustn't develop a "little mans" complex, and tries to verbally "write a checks" his gun can not get him out of.

In this case everyone involved louses: The animal is wounded, lost, and face a slow pointless death; the animal is wounded and charges the hunter and someone gets hurt if the PH can not provide a "charge stopping" shot with (yes you gusted it a "big bore rifle")
At the end of the day, regardless of your personal abilities / skills, your must select the caliber that is best suited to your intended target. "You don't want to bring a knife to a gun fight" when your life or reputation is at stake!

Hauptjäger