When I was living in Canada the 30-06 was the most popular choice in the 1980's for moose. I used a 270 and it did the trick shooting 150 grain speer grand slam bullets (heavy jacketed bonded). You might be thinking that you need a super duper magnum when the lungs are bigger than a beech ball and the heart is the size of a football. Always be ready for follow up shots and keep shooting until it is down. With a heart shot they have been known to travel 1/2 mile. All that said I currently use a 300 win mag for elk and moose.