I've seen 12 gauge shotgun slugs poke holes as big as a broomstick clear through both sides of a deer yet no blood trail. Alot depends on the location of the wound.More than halfway up the body may not leak any blood to speak of, regardless of the size of the holes. Holes in the lower one third tend to leak profusely. I've killed over 30 deer with various .22 centerfires and have yet to need a blood trail. Truth be told, it's been VERY rare to actually NEED a blood trail no matter what cartridge/caliber I've used as the VAST majority have gone down either within sight, within hearing or are easily found just by going to the spot they were last seen and looking ahead. A high percentage of my deer have been killed in what most folks would refer to as "heavy cover" too. Most just don't go very far after a well placed shot.
