"IF" no one made mistakes in this world then everybody would be perfect like you. First time hunt of a lifetime and the elk peeks out of the woods --you have trained for this for years --- you aim for for the rib cage at at an angle ---he is not straight on but your confident that your bullet will pass through a vital area --- your nervous as you have never seen such a big animal -- you dont have much time as the big bull is staring at you and ready to move at any time you try to steady your shot --- boom he moves as you finger pulls the trigger the bullet placement moves inches into the shoulder. The bullet fails to to take the animal down and the big elk goes into the thick woods. You spend 3 hours looking for him and then darkness falls. Only blood at the impact site.
Run the same scenario with a 300 ultra mag with another 100 grains on the bullet.
EOS
1. Where did I ever say I was perfect?
2. Use your 300 UM scenario and flinch at the shot and hit the bull in the paunch same result lost animal. Of course bigger and more powerful is better if you can handle it.....