Canister shot

Canister shot is a kind of anti-personnel ammunition used in cannons. It was similar to case and the naval grapeshot, but fired smaller and more numerous balls, which did not have to punch through the wooden hull of a ship. Canister shot has been used since the advent of gunpowder-firing artillery in Western armies; however, canister (or case) shot saw particularly frequent use on land and at sea in the various wars of the 18th and 19th century. The canister round is similar to a case (hence the confusion between case shot and canister shot) and is still used today in modern artillery, particularly in the main armament of tanks with smoothbore cannons.

Canister shot consists of a closed metal cylinder typically filled with round lead or iron balls, normally packed with sawdust to add more solidity and cohesion to the mass and to prevent the balls from crowding each other when the round was fired. At times when the supply of balls was limited, nails, scrap iron or lead, wire, and other similar metal objects were included. The canister itself was usually made of tin, often dipped in a lacquer of beeswax diluted with turpentine to prevent corrosion of the metal. Iron was substituted for tin for larger-calibre guns. The ends of the canister were closed with wooden or metal disks. Attached to the back of the metal canister was a cloth cartridge bag, which contained the round's gunpowder charge which was used to fire the canister from the gun barrel. A sabot of wood, metal, or similar material was used to help guide the round during firing from the cannon. Case shot is a similar type of ammunition, but instead of a tin can filled with metal balls, the case rounds carried a small powder charge. This powder was to break open the case and disperse the shrapnel.

The projectile had been known since at least the 16th century and was known by various nicknames in the 17th century such as hailshot or partridge shot. Rounds recovered from Henry VIII's warship Mary Rose' (sunk 1545) were wooden cylinders filled with broken flint flakes. When filled with rubbish or scrap (rather than round bullets) the round could be known as scrapshot or langrage. In 1718 Blackbeard aka Edward Teach armed his guns with a range of makeshift weaponry including langrage. Several of his cannon, still loaded with spikes and shot, have been recovered from the wreck site of his flagship, the Queen Anne's Revenge. Archaeologists have also retrieved conglomerations of lead shot, nails, spikes and glass from the site. Langrage was also found among the artifact assemblage of the Mardi Gras shipwreck, 4000 ft (1219 m) deep in the Gulf of Mexico. The defenders of The Alamo (1836) used old horseshoe nails and chopped up iron horseshoes to make their scrapshot.

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