Hmm, let's go extreme: a level 29 daily power that deals 7[W] damage with the same axe but it's got a +6 enchantment with d12-per-plus.
That's... let's say a normal roll would be 7d8+14, for an average of ~46 damage and a max of 70. And a crit would be 70+6d12, for an average of 109.