Common shell were hollow iron spheres filled with black powder and had slow-match fuses. The French howitzer bombs/shells were either 5.5 of 6 inches in diameter and when the shell detonated, the sphere would scatter between 25 and 50 fragments over a twenty-yard radius. They could also be used for ricochet fire. I would suspect the explosion of the round would be quite loud, something more than a modern mortar round.