The best answer to describe the difference caused by the change in mass of a projectile, when all other factors (launch angle, launch speed, etc.) are kept the same, is:
Increases in the mass of the projectile does not affect the range of the projectile.
This is because, in ideal projectile motion (neglecting air resistance), the range of a projectile depends primarily on its initial velocity and launch angle, not its mass. Therefore, while the cannonball and the car will have different ranges due to other factors like air resistance and shape, in a vacuum or under ideal conditions, their mass does not directly influence the range.