I know you said gunpowder isn’t used in warfare because it is so easy for a thruge to detonate it prematurely. Is it still used for civil purposes like mining?
I’m thinking if you have some miners or quarry drudges among your new joins that they might know how to aquire some. Anyway instead of using it in a firearm what about a mine? This is even better if you are a thruge because you can “wirelessly” command detonate any mines you’ve setup. If the mines are pre-buried then only you and your bandits should know where they are…