You have bullets but you have no rounds. What do you do? You lodge the bullet into a hole in the tree, use your knife as a firing pin, hit it with a rock and bang! Instant gun that can fight against the enemies’ rifles.
What do you do when you run out of landmines? You use a combination of bullets, explosives and urns to make an improvised 坛子雷. But what happened when the enemy refuses to step on your 坛子雷? You detonate them by shooting them.
Maybe Japan’s surrender had nothing to do with the atomic bombs dropped in Hiroshima and Nagasaki. Maybe they lost because of 坛子雷.