the disadvantage of not being tightly fitted into the bore (to do so would cause jamming). This causes the shot to "rattle" down the gun barrel and leave the barrel at an angle, unless wadding or a discarding sabot is used. This difference in shot and bore diameter is called "windage". Round shot has been totally replaced by modern shells. Round shot is used in historical recreations and historical replica weapons. In the 1860s, some round shots were equipped with winglets to benefit from the rifling of cannons. Such round shot would benefit from gyroscopic stability, thereby improving their trajectory, until the advent of the ogival shell. At the Battle of Bosworth there is an exhibition displaying where they found numerous lead cannon balls, or rather its correct term, round shot, when the archaeologists did some metal detection in the fields around the Bosworth Field. At Cragend Farm, Northumberland, similar lead round shot that appears to be from the same era was found in the Silo Field, using metal detection. Harry Hotspur owned the farm, and so this would tie in with the dates of the find. The shot was determined to consist of 98% lead, which would suggest that it has a stone within. See also Carcass (projectile) Chain shot Heated shot List of cannon projectiles Notes External links Photo of stone round shot from the Castello Sforzesco in Milan, Italy "A Guide to Geometry, Surveying, the Launching of Missiles, and the Planting of Mines" features 18th-century schematic drawings of cannonballs from the Muslim world via the World Digital Library Projectiles Artillery ammunition Balls French inventions