I have no moose experience, but have quite a bit of experience killing game with .44 and .45 caliber revolvers. I think my first choice would be one of the 300-grain bullets with a good, wide nose. I wouldn't feel terrible using a 250 Keith either.
I would want an alloy that was fairly hard, but would not shatter. My understanding is that some amount of tin helps with this. I would also shoot for bone and NOT expect it to go down right away, but would keep shooting until I had four feet in the air.
