While nitrocellulose is definitely the better option for smokeless powder, for example a mix of powdered sugar and sodium (per-)chlorate, which can be made from table salt once you have electricity, would probably work as well. Still, pretty hard to discover by accident - but there are plenty other alternatives as well, and you only need to find one of them.
I'm pretty sure it was in Rome:TotalWar, where this is one of the methods to fight elephants. I prefer massed archers and artillery because they are also useful for lots of other purposes, but the pigs are an option.Originally Posted by No brains