Jumping the String Follow Up - Getting the Itch Thread

[dlist777]

Last year we had this enormous thread on here.  https://www.njwoodsandwater.com/forums/topic/17901-getting-the-itch-to-purchase-a-xbow/#comments

Someone posted about buying a xbow.  After everyone posted saying whatever bow they happened to own was the best, the thread morphed into a whole discussion of whether a deer could have enough time between hearing a shot and the shot getting there to turn a good shot into a miss.  I think we were mainly discussing high speed xbows (like 400 FPS or so) and distances of 20-30 yards.  There was alot of disagreement of course.  Some name calling and then (as usual) no one actually changed their mind from what it had been at the beginning.  

I was firmly in the camp that if you had a good shot and a 400 FPS xbow, there was no way a deer could move enough to turn a good shot into a miss at those distances.  The main reason I was firm in that belief was that I believe when a deer is reacting it is dropping and not pushing or pulling itself down.  I posted all kinds of formulas (Sir Isaac Newton's) based on how fast you can drop based on gravity and the numbers seemed to show the deer could only move a few inches at most at those conditions (400 FPS xbow / 30 yards) even if they had instantaneous reaction.  

I stumbled across this video.  You can ignore the first 6 minutes.  They do a whole set of tests on jumping the string.  They base their tests on much slower FPS but one of the things they state at the beginning is that the deer is just dropping and can't move faster than gravity.  So, I was thinking this had confirmed my understanding.  But later they note that deer with their heads down seem to be able to move more as a reaction to the sound of a shot than deer with their heads up. 

Their conclusion was that when deer have their heads up, they are limited to just dropping (i.e. speed of gravity / falling object).  But, when their head is down, they kind of throw their head forward which pulls their chest down and lets them do kind of a crunch which would allow them to move faster than gravity.  They have a pretty convincing animation / video.  

Anyway, go to 6 minutes if you want to watch the whole thing or about 16:30 if you want to see the point about head up vs. head down.  

I think their presentation is pretty logical.  I have changed my mind.  Deer can move faster / more than I thought  Now, I'm not going to do anything different with this info.  I keep my shots short in any case.  But, it is interesting...

Video