Look at all the moose hunters in the Scandinavian countries who wack them with 6.5x55' s that should be all one needs to know. I am assuming the conditions in those countries are similiar to what one would find in Northern Maine or parts of Canada maybe a bit colder. Who cares about energy when your shot may be 50 yards to maybe 150 yards. They also put on Moose drives in those countries so the Moose are pumped full of adrenalin. It makes the killing power of those smaller calibers that more impressive.