The type of round and its size have a big effect on hydrostatic shock. A large caliber round, or an expanding bullet create more of a cavity as it passes through the human body. When that cavity is 'sucked' closed by the rest of the body and the sudden 'vacuum' a hydrostatic shock wave is created. In addition to hydrostatic shock, the bullet can lodge in a human body and increase the chance of infection and death. Removing the bullet can further threaten the target's life.
Some bullets have different effects.
A great deal of internal injury can be inflicted. This can be a lot better since it does not necessarily kill the enemy. If an enemy soldier is wounded then he must be evacuated and cared for, which can become a massive drain on enemy resources. A laser on the other hand would burn a whole in the target, cauterizing the wound. The subject would not bleed to death, suffer severe hydrostatic shock or be at risk from infection.