This is such a great video! 

https://www.youtube.com/watch?v=nRKyTmJeshk

Interesting to see how different slings react during release. With same ammo, string tension would be identical (at same throwing velocity)….so the different reactions is all due to the internal stiffness and inertia of the release cord.

I had a thought when you let go of the release cord, the sling becomes longer, so that the whole sling slows down…and this helps the ammo escape the pocket.  Similar to a figure skater slowing down spinning by sticking their arms out. This video shows it is not the entire sling motion as a system but rather the individual motion of the release cord along with pouch resistance to opening that determines how the ammo escape.

I like the idea of the fin to slow down the release cord.

But looking at the slow motion video from Acro, don’t we want the release cord to move faster, not slower??


To me, it really looks like the ammo pulls hard on the release cord as the sling spins (applying tension on the release cord)….and then the release cord “snaps” out of your hand during release (like a cable snapping or breaking from too much tension).

I do not know much about cable breaking math or formulas. The motion and acceleration of the release cord should follow the equations that describe a cable breaking I would think. Release cord stiffness, mass, reaction to wave propagation…some of these things must be driving the release cord reaction to the sudden elimination of the cord tension at the moment of release.

Intuitively more tension on the release cord should make it accelerate or open the pocket faster. Faster opening pouch could lead to higher accuracy or possibly more distance (less pouch drag)

A longer sling increases centripetal acceleration….that would increase cord tension. Heavy ammo would increase tension too.

I wonder if an asymmetric pouch would hold the ammo closer to the release cord. Would that pull harder on the release cord??  Globally I have to think both release and retention cord each carry 1/2 the tension….but locally if we move the ammo to the end of the release cord instead of “half a pouch” distance away from the end of the release cord, the “effect” would be quicker release cord reaction???

Maybe just tie paracord knots such that the ammo sits in 3 points (football kicking tee)…..and offset the knots towards the release cord side of the pouch?? I have seen the cobra shaped pouch and the Y-sling pouch. No idea how they work, but both are asymmetrical.