Lead shot is a collective term for small balls of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

. These were the original projectile

Projectile

A projectile is any object projected into space by the exertion of a force. Although a thrown baseball is technically a projectile too, the term more commonly refers to a weapon....

s for musket

Musket

A musket is a muzzle-loaded, smooth bore long gun, fired from the shoulder. Muskets were designed for use by infantry. A soldier armed with a musket had the designation musketman or musketeer....

s and early rifle

Rifle

A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

s, but today lead shot is fired primarily from shotgun

Shotgun

A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

s. It is also used for a variety of other purposes. It was originally made by pouring molten lead into wooden molds and later more economically mass-produced using a shot tower

Shot tower

thumb|The Shot Tower, Bristol, EnglandA shot tower is a tower designed for the production of shot balls by freefall of molten lead, which is then caught in a water basin. The shot is used for projectiles in firearms.-Process:...

.
Producing lead shot from a shot tower was pioneered by William Watts of Bristol

Bristol

Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

 who adapted his house on Redcliffe Way by adding a three-storey

Storey

A storey or story is any level part of a building that could be used by people...

 tower and digging a shaft under the house through the caves underneath to achieve the required drop.