My name is Chen Tiezhu, a 21st century mechanical engineer. When I opened my eyes, I became Li Yunlong, the leader of the Independent Regiment in the 26th year of the Republic of China. The memory is confused, the troops are in disarray, the northwest of Shanxi is full of people dying of hunger, the Japanese occupy the county town, and the people are like grass and grass. There is no system, only the modern military industry knowledge in the mind. Short of guns and ammunition, they rely on drawings to make earthen mines and using iron pots to make steel. The Japanese army had electric knives and the Puppet Manchukuo developed rockets. Their technology far exceeded history. Using the mechanical database as a basis, I started from a bullet, modified guns, built cannons, and built an arsenal. Every step is tested with life, and every inch of progress is stained with blood. In these troubled times, I don't believe in fate, only in calculation and craftsmanship. From Cangyun Ridge to the Yalu River, they fought countless battles, just to straighten the skewed technological line and protect the mountains and rivers behind them.
