The backstop. Usually a sheet of metal, set at an angle, bullets striking it are deflected down. Some strike a bed of sand, some water, some are deflected into a large round metal pipe, where the bullets spin until they stop.
A cowboy gun is normally a revolver, which has six holes for the bullets to go in. But the cowboy would only put five bullets in for safety reasons. It was to stop the gun firing whilst it is in his pocket.
it alows them to keep everyone safe for example if someone walks down range and he calls for everyone to stop firing then and no one listens then the person that is down range could get killed
Do you mean "what is an automatic Rifle". Any rifle that keeps firing as long as you hold the trigger down is an automatic rifle. It will only stop when you let go of the trigger or run out of bullets
Bullets
Sure. What it can stop will depend on the thickness of the iron, and the capabilities of the projectile being fired at it.
At the end of the first movie matrix
Depends on caliber & velocity of the bullet.
Yes
By convincing the terrorists to stop firing at her and to accept her existence.
That depends on the level that the vest is rated for. For example, a NIJ levvel IIa vest will stop some types of bullets. A NIJ level II will stop even more types of bullets. A NIJ level IIIa will stop still more types of bullets. NIJ levels are I, IIa, II, IIIa, III, IV, and Special.
spray them with chili
Kevlar is used to stop some bullets. Normally it will stop pistol rounds but other rounds , especially an anti tank round.