PART1-I Upgraded My Musket to a Gatling Gun—Now Every Monster Within Range Is Just Target Practice.

What the story is about

After being reincarnated into a world where people awaken combat classes to fight invading monsters, Li Yang is assigned the supposedly weak Gunslinger class. His knowledge of modern weapons lets him create a devastating Gatling gun and turn his class’s supply drops into an arsenal, rapidly making him a standout fighter.