Gunstones represent the earliest form of projectile fired from gunpowder artillery. They served as ammunition during the initial phase of the gunpowder era, when the first large-caliber guns, known as bombards, were developed in Europe. These projectiles were the standard for early cannon before metal casting techniques advanced sufficiently to produce reliable iron shot.
Physical Characteristics and Composition
Gunstones were spherical projectiles crafted primarily from natural materials such as granite, limestone, or other suitable types of cut stone. Stonemasons were employed to dress the stone to an exact diameter, ensuring a fit slightly smaller than the gun’s interior, known as the windage.
The size of gunstones varied dramatically depending on the size of the cannon, with some colossal examples reaching immense proportions. For instance, the famous bombard Dulle Griete was designed to fire a granite ball weighing approximately 700 pounds. The relative lightness of stone compared to metal reduced the strain on the barrel, which was an advantage for early, less-robust cannons.
Role and Function in Early Artillery
Gunstones acted as a “remote battering ram,” delivering kinetic energy against static targets like castle walls and siege fortifications. Gunners loaded the stone into the muzzle, followed by a charge of gunpowder. Wadding was often used to pack the shot tightly against the powder charge, helping to reduce the windage and improve the consistency of the blast.
Stone projectiles were highly effective in siege warfare, causing significant structural damage to masonry. Upon striking a hard surface, a gunstone would often shatter, delivering destructive energy and causing fragmentation-based casualties. However, the inconsistent density and relative fragility of stone resulted in less predictable flight paths and limited the overall destructive force.
Historical Context and Replacement
Gunstones were the dominant form of cannon ammunition from the late 14th century until the mid-15th century. Their use was tied to metallurgical technology, as producing large, perfectly spherical iron balls was initially difficult and expensive. The prevalence of gunstones changed significantly after the mid-1400s, when advances in iron casting made the mass production of cast-iron cannonballs a more viable option.
The greater density of iron provided a much heavier projectile for a given caliber, resulting in superior momentum and destructive power against fortifications. The shift to iron projectiles allowed for the development of smaller, more mobile cannons that fired the denser shot, accelerating the obsolescence of the stone projectile. Evidence of their existence can still be found by archaeologists, particularly in medieval siege sites and shipwrecks from the early age of sail.