Anyways, this came up in the chat and I would like to mention it here as well.

My idea is that we don't know who or when invented the gunpowder (perhaps there are multiple types and recipes) but the nation which mostly promoted its use was the Golden Horde's orcs. Both through allowing to materials and knowledge spread through their equivalent of the Silk Road and also through seeing orcs fighting with guns.

Does this lore snippet sounds acceptable to you?