People who 'need' blood trails would probably do well to rethink their shot placement as well. A shot through 'shoulders' which doesn't break major bone and disable an animal (so that it dies nearby) is not a reliable way to create a blood trail via the voluminous chest bleeding it will likely produce; the muscles tend to help seal the wound. On the other hand a shot behind the shoulder/leg area, especially a through-and-through side-to-side chest shot with a well-expanding bullet, will often lead to rapid lung collapse which allows blood to pool inside the chest cavity. If the holes are low there will likely be a good blood trail. If they are higher up the blood may never reach the level where it is expelled from the hole(s) in much volume.
Big animals can surprise people who are accustomed to killing smaller, couple-hundred-pound animals. Being closer, hitting them (well) more than once, and hearing sound evidence after the shot are all useful ways to find an animal after the shot(s).
