The "trigger string" is 41-inches long. The "retained string" totals 39.5" long, including the finger loop. The "double string", which goes to the retained string, comes away from the pocket 12-inches. I suppose all these string lengths are pretty arbitrary, and a person should use whatever lengths he/she can spin easily.

When I first loaded the sling with a golf-ball, I noted the ball was in actual contact with very little of the pocket leather. I figured the "unneeded" leather could be cut away to reduce air drag during "spin-up". This resulted in the pocket shape pictured. The pocket sides are cut in about 7/8-inch from the original straight triangular shape.

This skinny, but 3-cornered, pocket is a very stable golf-ball container, AND can handle much larger roundish objects just fine. I've thrown large apples with it, ...though not very far. They're just too heavy for a lightweight grandpa. Roundish "ammo" works by far the best. There seems to be no problem in slipping the ammo out of the pocket when the trigger string is released. Grossly football shaped or cylindrical "ammo" does not sit in the pocket very well, is probably dangerous to try, and probably should not be used.

I put the retaining loop on my ring-finger (not the "bird" finger), to be able to hang onto more string. My spin is vertical, off to the side, with underhand delivery. I'm a lefty.