This data pack is a remake for 1.16 of an 1.12 only one command by Cimap (Youtube). It was created for headmaster_bruce's request.

This remake data pack (see above) adds working cannons to minecraft. Create a cannon by throwing gunpowder and an iron block on the top of any stairs. You can decide which stairs to make so the cannon fits with the environment. Make sure the stairs are in the correct direction. But don't worry, you can always break the stairs and get everything back.

You cannot place cannons too near each other. There must be a distance of at least 3.6 blocks between one cannon to another.

Throw TNT on the back part of your cannon to shoot a ball. The ball flies until it touches a block, then it blows up.