I am very puzzled....
When I practice slinging after dark, I do the throws with an empty pouch in my apartment.
Every time the motions flow just right, and the "whoosh-snap" sounds at its most uplifting, my sling seems to bite my finger!
It feels as though either the retention cord or the release toggle whips my index finger on the slinging hand.
My sling is 1/4 inch diameter paracord (not very flexible) with a webbing toggle (not much heavier, but slightly stiffer). I use an Apache grip - i.e. both retention and release cords are held between the tip of my thumb and the first knuckle of my index finger.
Regardless of throw style (figure-8, side, golf, up, down, across, upside-down, you name it), my index finger gets a spanking whenever I get a really good hard throw.
This happens most easily with an empty pouch or small/light projectiles, and only during the strongest/fastest throws. I would guess it's either the increased sling speed or the reduced oscillation damping normally caused by a heftier stone. It occasionally happens with heavy stones too, when I really put my back into it.
Thus I imagine it might be one of the following:
-a snap during release, in which the retention cord becomes taut and tries to displace my index finger
-some odd toggle trajectory on its way out of my grip, perhaps I whack my hand into it before it has a chance to overcome the toggle's inertia
-as the release cord swings into alignment with the retention cord, it needs to sharply decelerate (once in line, it remains in line) and thus transfers its momentum to the pouch. The pouch, being a heavier object on the cord, and interrupting the smooth transmission of waves, induces some combination of reflected/transmitted waves which then travel down the retention cord and cause it to strike my hand. (what do I know)
Due to the wide variety of throw styles, angles, etc. attempted, I have suffered stings from the tip of my index finger to the center of the back of my hand, to the joint between my index finger and thumb.
All attempts to observe my throws directly or in the mirror have failed. I've asked others to watch and try to see what's happening, but the motion is just too fast.
Have others encountered this phenomenon?
Any ideas what it might be, and how it could be countered?
Would changing the pouch weight / cord weight / cord flexibility do anything?
I would like to continue using high-power throws, preferably without looking like a kid whose father caught him with a hand in the cookie jar.
Suggestions appreciated,
-pancaker