bobcat wrote:i doubt it was your tip. You gotta hit them low if you want them to leak.
When deer are hit in the lungs the only blood they project at first is aspirated(blown from nose as they breathe) in the form of really tiny droplets in the form of a fine mist. The distance between these spatter patterns on the ground is obviously proportional to it's speed and with every exhale. It is very difficult to track. At some point the lungs begin to fill up a bit to a level above the trachea and/or arrow hole(s) and larger droplets are blown out of the nose/arrow holes. Obviously these droplets turn into "globs" of blood as the animal slows down(due to oxygen deprivation) and tracking becomes easier and easier. Obviously large cut BH's can be exception to this by adding droplets from the external tissue cut/bleeding proportional to it's size entrance/exit, but the external rib area does have a limited blood flow, and the large cut does help that initial trail by providing higher quantity of cut veins/arteries to bleed in more volume.
IMHO I've found that blood trails on double lung hits in the center and above are tough to find on an animal that took off running for at least the first 5-10 breaths of the animal, and that could be almost 100 yds or more depending upon it's speed and the height of the hit.
I personally use a small BH and deal with this all the time. My belief is that you are simply suffocating the animal by popping his lungs and depriving him "enough" oxygen to stay conscious. The blood trail has nothing to do with killing the animal in double lung hits. I believe that the reason they run so far is proportional to the holes you punched and how effective the bags(aka lungs) hold air long enough to be absorbed by the alveoli that remain uncovered by blood. This is obviously proportional to the amount of capillaries which are cut by the BH's damage and how quickly the alveoli are covered by the blood hemorrhaging internally. At some point this essential drowns the animal. Obviously blood is thicker and stickier than water so it's much more effective.
For me and my little BH's I expect a 50-150yd trail anyways...
I've often left a marker where I hit the deer and go up 100 yards in his direction of last travel and try zig zagging laterally 50 yds each way to locate some blood rather than obsessing for that first few drops near the site of impact.
This usually helps speed the process up for me in recovering deer.
. The weird thing is that I shot her at 25 yards, perfectly broadside... a little high in the shoulder but a perfect double lung shot. She made it about 75 yards and piled up,,, but not one drop of blood hit the ground 
. I looked for about two hours before I got lucky and found her... maybe it was the high shoulder hit but now I'm a little concerned about the Boltcutters,,, may have to saddle the Slick Tricks back up!
