Hey all, so I was just thinking - in Mistborn HoA, it says that in the old days when allomancers were fairly new and their powers weren't diluted by generations, multiple soothers could take hold of koloss and kandra. In Vin's day, to achieve that effect, you need duralumin + brass/zinc. So that got me thinking... In the old days, could you use duralumin and bronze to pierce a coppercloud?
I don't have any exciting theories, I just wanted to put that out there. Also, I don't have an exact source for the HoA reference but I'm fairly certain it says that somewhere.