If a gun is set up in Shandong Peninsula, can it hit Japan?

What is the concept of 800 Li? Guns are impossible. During World War II, Germany developed a missile, V 1 missile, which is the earliest missile in the world.

A missile that appeared and was used on the battlefield. Germany used this missile to launch from the European continent to the British mainland. This missile fired.

The distance is four hundred and eighty li. It hasn't reached the point of 800, and the range of the V2 missile that was later improved in Germany reached 640, too.

It didn't reach 800 Li. A bullet was as powerful as gunpowder, and even the most advanced missiles in the world at that time couldn't hit it.

With a range of 800 Li, how about a gun?