According to the US Army Borden institute the fact that higher energy results in greater wound damage has been known since studies were conducted during the Civil war and every study since. However, as has been said, the type of bullit as in expanding, fragmenting, or upsetting has a great effect and the type of tissue the bullet strikes, especially bone results in more energy causing greater damage to the body. Other factors mentioned included hitting a major artery, cavitation bullet shape construction and size etc. A diameter larger than 5-6mm is not recommended nor is soft point ammo to prevent lethal wounds from the surgeons point of being more humane. So yes energy is important, so is size and construction but placement and what is damaged is more important than all.