IMO depends on if one is an avid shooter with lots of practice year round or just an average joe using his rifle in hunting season only. Heart/lung shot or average shooter.
I have seen moose going miles with multiple shot wounds just not in the exact right place. I think that for moose the impact of the bullet is very important as the damage made by it, will give you time for a follow up shot while it's recovering from the impact.
So with common calibers 30-06 in 180gr. would be a very good start. Started hunting moose with an 8mm mauser that was given down to me and then moved on to 300WSM wish i like very much.
Just think that 270 is a little bit on the shallow side for moose, .300 way better. 270 is good caliber for deer in 140gr. tought.