Canister shot in the context of "Artillery piece"

Artillery consists of ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons were developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower.

Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannon, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called barrel artillery, cannon artillery or gun artillery) and rocket artillery. In common speech, the word "artillery" is often used to refer to individual devices, along with their accessories and fittings, although these assemblages are more properly called "equipment". However, there is no generally recognized generic term for a gun, howitzer, mortar, and so forth: the United States uses "artillery piece", but most English-speaking armies use "gun" and "mortar". The projectiles fired are typically either "shot" (if solid) or "shell" (if not solid). Historically, variants of solid shot including canister, chain shot and grapeshot were also used. "Shell" is a widely used generic term for a projectile, which is a component of munitions.

In artillery, a grapeshot is a type of ammunition that consists of a collection of smaller-caliber round shots packed tightly in a canvas bag and separated from the gunpowder charge by a metal wadding, rather than being a single solid projectile. When assembled, the shot resembled a cluster of grapes, hence the name. Grapeshot was used both on land and at sea. On firing, the canvas wrapping disintegrates and the contained balls scatter out from the muzzle, giving a ballistic effect similar to a giant shotgun.

Grapeshot was devastatingly effective against massed infantry at short range and was also used at medium range. Solid shot was used at longer range and canister at shorter. When used in naval warfare, grapeshot served a dual purpose. First, it continued its role as an anti-personnel projectile. However, the effect was diminished due to a large portion of the crew being below decks and the addition of hammock netting in iron brackets intended to slow or stop smaller shot. Second, the shot was cast large enough to cut rigging, destroy spars and blocks, and puncture multiple sails.

Snake shot, rat shot, or dust shot, more formally known as shotshell (a name shared with the shotgun shell) or canister shot, refers to handgun and rifle cartridges loaded with lead shot canisters instead of bullets, intended for pest control (essentially small arms canister shot). The main targets for such ammunition are snakes, rodents, birds, and other pests at very close range.

The most common snake shot cartridge is .22 Long Rifle loaded with No. 12 shot. From a standard rifle these can produce effective patterns only to a distance of about 3 m (9.8 ft), but in a smoothbore shotgun (or garden gun) that can extend as far as 15 m (49 ft).