<P> Grenade rounds use exploding projectiles to increase long range lethality . These are currently experimental, but the British FRAG - 12, which comes in High Explosive (HE), High Explosive Armor - piercing (HEAP) and High Explosive Fragmenting Antipersonnel (HEFA) forms, is under consideration by military forces . </P> <P> Flexible baton rounds, commonly called bean bags, fire a fabric bag filled with birdshot or a similar loose, dense substance . The "punch" effect of the bag is useful for knocking down targets; the rounds are used by police to subdue violent suspects . The bean bag round is by far the most common less - lethal round used . Due to the large surface area of these rounds, they lose velocity rapidly, and must be used at fairly short ranges to be effective, though use at extremely short ranges, under 3 m (9.8 ft), can result in broken bones or other serious or lethal injuries . The rounds can also fly in a frisbee - like fashion and cut the person or animal being fired at . For this reason, these types of rounds are referred to as less - lethal, as opposed to less - than - lethal . </P> <P> Gas shells spray a cone of gas for several meters . These are primarily used by riot police . They normally contain pepper gas or tear gas . Other variations launch a gas - grenade - like projectile . </P> <P> Rock salt shells are hand loaded with coarse rock salt crystals, replacing the standard lead or steel shot . Rock salt shells could be seen as the forerunners of modern less - lethal rounds . In the United States, rock salt shells were and are sometimes still used by rural civilians to defend their property . The brittle salt was unlikely to cause serious injury at long ranges, but would cause painful stinging injuries and served as a warning . British gamekeepers have used rock salt shells to deter poachers . Rather than get into a physical confrontation, they stalk the poachers, making themselves known by a loud shout of "Run!" just before firing, to avoid hitting the now - fleeing subject in the eyes . </P>

Where did the 12 gauge shotgun come from