Shot (pellet)

, Melbourne, Australia Producing lead shot from a shot tower was pioneered in the late 18th century by William Watts of Bristol who adapted his house on Redcliffe Hill by adding a three-storey tower and digging a shaft under the house through the caves underneath to achieve the required drop. The process was patented in 1782. The process was later brought above ground through the building of shot towers. Molten lead would be dropped from the top of the tower. Like most liquids, surface tension makes drops of molten lead become near-spherical as they fall. When the tower is high enough, the lead droplets will solidify during the fall and thus retain their spherical form. Water is usually placed at the bottom of the tower, cooling the lead immediately upon landing. Roundness of manufactured shot produced from the shot tower process is graded by forcing the newly produced shot to roll accurately down inclined planes. Unround shot will naturally roll to the side, for collection. The unround shot was either re-processed in another attempt to make round shot using the shot tower again, or used for applications which did not require round shot (e.g., split shot for fishing). == Sizes ==

lead shot Shot is available in many sizes for different applications. The size of numbered shot decreases as the number increases. In hunting, some sizes are traditionally used for certain game, or certain shooting situations, although there is overlap and subjective preference. The range at which game is typically encountered and the penetration needed to assure a clean kill must both be considered. Local hunting regulations may also specify a size range for certain game. Shot loses its velocity very quickly due to its low sectional density and ballistic coefficient (see external ballistics). Generally, larger shot carries farther, and does not spread out as much as smaller shot. Buckshot Buckshot is a shot formed to larger diameters so that it can be used against bigger game such as deer, moose, or caribou. Sizes range in ascending order from size #B (0.17 in, 4.32 mm) to Tri-Ball. It is usually referred by the size, followed by "buck", e.g. "#000" is referred to as "triple-aught buck" in the United States or "triple-o buck" in other English speaking countries. Buckshot is traditionally swaged (in high volume production) or cast (in small volume production). The Bliemeister method does not work for shot larger than #5 (0.12 in, 3.05 mm), and works progressively poorly for shot sizes larger than about #6. Lead shot comparison chart Below is a chart with diameters per pellet and weight for idealized lead spheres for U.S. Standard Designations with a comparison to English shot sizes. == Applications outside firearms ==

When used as a pourable/mouldable weight, lead shot may be left loose, or mixed with a bonding agent such as epoxy to contain and stabilize the pellets after they are poured. Some applications of lead shot are: • As ballast in various situations, especially where a dense, pourable weight is required. Generally, small shot is best for these applications, as it can be poured more like a liquid. Completely round shot is not required. • Stress testing: Providing variable weights in strength-of-materials stress-testing systems. Shot pours from a hopper into a basket, which is connected to the test item. When the test item fractures, the chute closes and the mass of the lead shot in the basket is used to calculate the fracture stress of the item. • Hydrometers: use a weight made of shot, since the weight has to be poured into a narrow glass vessel. • Split shot, a larger type of lead shot where each pellet is cut part-way through the diameter. This type of shot was formerly commonly used as a line weight in angling. They are no longer solely manufactured from lead but instead are often made from softer materials that can be easily pressed onto the fishing line instead of being closed in a crimp using pliers, as was once common. • The heads of some dead blow hammers are filled with shot to minimize rebound off the struck surface. • Shot belt: some scuba diving weight belts contain pouches filled with lead shot. • Many blackjacks and saps use lead shot as a flexible weight to deliver high energy blows while minimizing damage from sharp impact force (similar to the way it is used in dead blow hammers). • Loudspeaker stands can be filled with lead shot for additional acoustic decoupling, as well as stability. • Model rocketry: to add weight to the nose of the rocket, increasing the stability factor. • Due to its heat capacity and low thermal conductivity at low temperatures, lead shot has been used as a suitable material for a regenerator in Stirling engines and thermoacoustic cryocoolers. • Due to lead's high density, it is used to attenuate radiation, especially X-rays and gamma rays. Lead shot may be enclosed in a vest, blanket, or bag that is placed around a point source for radiation shielding. == Bird lead poisoning ==

Lead shot-related waterfowl poisonings were first documented in the US in the 1880s; by 1919, the spent lead pellets from waterfowl hunting were positively identified as a major source of deaths of bottom-feeding waterfowl. Once ingested, stomach acids and mechanical action cause the lead to break down and be absorbed into the body and bloodstream, resulting in death. "If a bird swallows only one pellet, it usually survives, although its immune system and fertility are likely to be affected. Even low concentrations of lead have a negative impact on energy storage, which affects the ability to prepare for migration." Foraging studies of the endangered Californian condor have shown that avian scavengers consume lead fragments in gut piles left in the field from harvested big game animals, as well as by the consumption of small game, or "pest animal," carcasses that have been shot with lead-core ammo, but not retrieved. Not all lead exposure in these circumstances leads to immediate mortality, but multiple sub-lethal exposures result in secondary poisoning impacts, which eventually lead to death. Lead shot is also banned within an eight-county area in California designated as the condor's range. As of 2011, thirty-five states prohibited lead shot use in such specially-specified areas when hunting. In an effort to protect the condor, the use of projectiles containing lead has been banned for hunting wild boar, deer, antelope, elk, pronghorn, antelope, coyote, squirrel, and other non-game wildlife in areas of California designated as its habitat range. The bald eagle has similarly been shown to be affected by lead originating from dead or wounded waterfowl—the requirement to protect this species was one of the biggest factors behind laws being introduced in 1991 by the United States Fish and Wildlife Service to ban lead shot in migratory waterfowl hunting. Hunting restrictions have also banned the use of lead shot while hunting migratory waterfowl in at least 29 countries across by international agreement, Depending on hunting laws, alternatives to lead shot are mandated for use by hunters in some locations when hunting migratory birds, notably waterfowl. In the US, the restrictions are limited to migratory waterfowl, while Canadian restrictions are wider and apply (with some exceptions) to all migratory birds. The use of lead has been banned for all hunting activities in the Netherlands as of 1992. The Missouri Department of Conservation introduced regulations in 2007 in some hunting areas requiring the use of non-toxic shot to protect upland birds. Some clay pigeon ranges in the US have banned the use of lead after elevated levels of lead were found in waterfowl, small birds, mammals and frogs in their vicinity. Steel shot can be as hard as some barrels, and may therefore damage chokes on older firearms that were designed only for use with softer lead shot. The higher pressures required to compensate for the lower density of steel may exceed the design limits of a barrel. Within recent years, several companies have created non-toxic shot out of bismuth, tungsten, or other elements or alloys with a density similar to or greater than lead, and with a shot softness that results in ballistic properties that are comparable to lead. These shells provide more consistent patterns and greater range than steel shot. They are also generally safe to use in older shotguns with barrels and chokes not rated for use with steel shot, such as for bismuth and tungsten-polymer (although not tungsten-iron) shot. Unfortunately, all non-lead shot other than steel is far more expensive than lead, which has diminished in its acceptance by hunters. == See also ==