Something we would all like is to consistently be able to shoot into a 6” circle at 20 yards, since that is about the size of a deer’s vitals.
But what does it take to do that? Try something: Draw your bow and see how steady you can hold it on target. While at full draw, close one eye and aim at a small dot or something across the top of a knuckle on your bow hand, and see how much that knuckle moves around as you hold it out there. Mine seems to move about an eighth of an inch max off the target, during the short time I can hold my recurve steady at full draw. I can prove that by making two marks 1/8” apart on my knuckle, and I can always keep the target within the two marks.
If that eighth of an inch involuntary movement were the only thing that affected my arrow, how much would it affect my group on a target 20 yards away? The answer, as illustrated by the diagram, is that that 1/8” movement alone would cause me to have a 6” group at 20 yards. That’s if I have no other deflection errors, by which I mean an unwanted movement off target by one end of the arrow or the other. Other causes of deflection errors could be a poor release, grabbing the grip with the bow hand on release, torqueing the string, collapsing the bow arm, bow limbs out of alignment, arrow spine problems, and probably a few dozen others.
Now sometimes I can shoot better than a 6” group at 20 yards, and I can guarantee you that the sum of all my other aiming, form, and equipment errors is not zero. How is that possible? I can only take on faith what many others have said: shoot a lot of arrows and your brain will learn the hand/eye coordination to send the arrows where you want them to go. I have to assume that when I’m “on,” my brain is sending a signal to my hand to release the arrow at a point when I’m not shooting at the extreme of that unavoidable 1/8” movement.
Wonder why some shots hit way off the mark when it seems like you fired them exactly the same as the last shot? How would it affect my shot if I did something that caused my normal 1/8” variation to be 1/2"? As the diagram shows below, a 1/2" deflection error will result in a miss of more than 13” at 20 yards! A deflection error compounds with the distance from the bow: 13” at 20 yards, 26” at 40 yards, and so on, which gives this the potential to be an error of much greater magnitude than other types of human or equipment errors we might make.
y/28 = x/(720 + 28)
x = (748*y)/28
if y = .125”, then x = 3.34”
if y = .5”, then x = 13.4”
Add in all the other avoidable and unavoidable errors we’re apt to make, and the wonder to me is not how poorly we shoot, but how we can shoot as well as we do. Consider that those of us who shoot using the swing draw method never really stop deflecting the arrow from the point we start our draw until release, although some may pause momentarily just before release. And yet to achieve better than a 6” group at 20 yards, the arrow has to fly out of the bow with no more than a 1/8” deflection error for every shot in the group! The human mind is truly a remarkable thing to be able to compensate on a sub-conscious level and direct the hand to do what the eye sees with such precision.
Topic: Deflection errors (Read 2213 times)
