Before the operation, Malin asked Tuojin and his team to discuss the plan—such a caravan was definitely armed, and the troops that inspected them upon entering the city confirmed they were carrying Revolvers and the oldest model of breech-loading rifles from the workshops.
These rifles are currently widespread all over the world, from the armies of friendly nations fighting Chaos alongside Sydney, to the hunting grounds of wealthy Nobles, from caravans that got Malin's discarded goods through connections to the Adventurers' Guild which still faces a supply-demand issue. Malin's first batch of bolt-action rifles held a reputation akin to the AK47.
Robust, durable, and produced in large quantities, they were sold everywhere.