FYI to my fellow readers: If you ever get isekai'd and end up re-inventing cannons... Don't stand directly behind the cannon. That is not a safe spot. Especially not behind one that is experiencing its first field test. The recoil could cause the cannon to slip out of its restraints and hit you. Or the back could explode and hit you. Or the whole wheeled assembly could roll back into you. Or if you've messed up the balance, the whole thing might flip over onto you.