A
shotgun shell is a self-contained
cartridge typically loaded with multiple metallic "
shot", which are small, generally spherical projectiles. Traditionally
lead was used, but increasingly steel, tungsten or bismuth shot has replaced lead, due to laws designed to protect the environment. A single, large projectile known as a
shotgun slug can also be used, and numerous specialty rounds such as
less-lethal rounds (i.e.
beanbag rounds),
flechette rounds, lead-dust rounds for
door-breaching are also available. An old non-lethal shotgun load consisted of a shotgun shell loaded with
rock salt, which could inflict very painful, but rarely deadly, wounds, and was therefore popular for scaring away trespassers.