The 18-caliber 274-millimeter Modéle 1870 gun fired an armor-piercing, shell while the gun itself weighed . The gun fired its shell at a muzzle velocity of and was credited with the ability to penetrate a nominal of wrought iron armour at the muzzle. The armor-piercing shell of the 19-caliber 240-millmeter Modele 1870 gun weighed while the gun itself weighed . It had a muzzle velocity of and was credited with the ability to penetrate a nominal of wrought iron armor at the muzzle. The 138-millimeter gun was 21 calibers long and weighed . It fired a explosive shell that had a muzzle velocity of . The guns could fire both solid shot and explosive shells.