Generally speaking, moose are not hard to kill with proper bullet placement. But often, they don’t realize that they should be dead, and it takes a little time for them to fall down. First I would recommend a premium bullet, that retains a high % of it’s weight. Personally any of the 30’s (.308 Win.) and up, is my suggestion. Though the 6.5’s will do the trick, my wife’s first bull was taken with a .264 Win.Mag. Her most recent was with a .338 Win. Mag. Larger calibers, with proper placement certainly are a plus. memtb