Those people had mastered the manufacturing methods of Great Chu's Firearms, and this was an immense temptation for Wu Tuo. Although Wu Tuo Kingdom had developed Gunpowder, and could use it to conduct campaigns far and wide, compared to Firearms that were less lethal but much more flexible and safe, Gunpowder was much more troublesome to handle, and one could easily blow oneself up if not careful.
This kind of incident had occurred more than once or twice. On one occasion, when Wu Tuo Kingdom's army had occupied a small country, they were ambushed by the people there at their Gunpowder depot. The Wu Tuo soldiers suffered heavy casualties, and the remaining troops were forced to retreat and temporarily gave up the offensive.