How powerful is the bullet? If you know the structure of the bullet, you will know that the reason why the bullet can be shot out of the gun is that there is a certain amount of gunpowder inside the bullet. When the firing pin in the gun hits the bottom of the bullet, it will ignite the gunpowder in the bullet, thus providing kinetic energy for the bullet when it is fired. Therefore, if the performance of the gun is better, the kinetic energy of the bullet will be relatively greater.
Kinetic energy is only part of the reason why bullets can cause damage to targets. It is understood that when the bullet is fired out of the gun, it will also rotate rapidly. When the bullet enters the body, the gravity generated by the rotation of the bullet will tear the surrounding cell tissue. If the bullet happens to be near the artery, it will cause massive bleeding.
Source: @adtattoos