Ammo
There is non lethal training ammunition (Simunition etc...) and there is less lethal ammunition (flexible projectiles, like sock rounds, and non flexible, plastic, wood, etc). Less lethal ammunition is widely used by many police dept's in the form of bean bags, and their use is not only for riot control, they are very effective at subduing violent people. There is always the potential to cause death when using such tools, but the risk is low if used as intended. Simunition, although called non lethal, has the potential to cause death, especially when launched from one of their AR uppers (ouch!).