C820 Bronze Earth Cannon 1
Although the gunpowder had been successfully produced, it was still difficult to mass produce it.
Firstly, the gunpowder could only be produced by manpower. Secondly, it had high requirements on the human body. Thirdly, the problem of the materials. The three types of materials had to be ground into powder to be able to mix well. Only then could the power of the gunpowder be fully displayed
