I've had a Ten Point Elite, shooting 125 Spitfire mechanicals since '95. I Hunt from a ground blind off a bait pile at 30 yards. I've harvested 8-10 standing (still) and broadside deer. However, due to lack of blood trail on leaves I've lost 5-6 deer. I now hunt mainly over snow to avoid that.
The best theory on blood loss I've come up with is that the bolt deflects from the area of impact (lungs) radically enough to travel through the intestines and on exiting carries out enough intestines to plug the exit hole, thus restricting blood flow.
With all the deer I've harvested (or wounded) the bolt has passed completely through, landing well on the other side.
Because of the deer I've tracked and retrieved over snow I've written off the following offered theories: The deer are moving from the bolt release sound but I just don't see it. The blades on the Spitfire didn't open. My bow string is stretched and the bolt is not flying straight. I would welcome any other theories.