I did watch a Primos video once that showed slow motion footage of all the deer shot and marked the deer's back right as the shot was heard going off.........when the arrow hit......the deer had already gone down getting ready to pounce away. In some cases it was pretty dramatic how low they dropped before the arrow got there. They also said that this is why they aim for the heart......low in the chest. If he doesn't duck you get the heart and bottom lung.......if he does you are right in the middle of the chest.
Until I see a deer do that in the woods I will keep aiming for where I want to hit.........and sighting my bow in dead on. I have enough things going through my mind without trying to guesstimate how low my arrow might hit [

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It was an interesting video though.