1.) leather-pouched slings
(all bindings are waxed hemp)
left is flax strings, thin, flexible leather pouch, flax brush
middle is wicker strings, thin stiff leather pouch (waxed), flax brush
right is flax strings, thick, flexible leather pouch (oiled and waxed), brush from lamb's wool
the right one is my favourite sling so far. It's 27.5 " (folded), quite heavy but not slow on release.
The leather was watered, kneaded, cut and shaped, then filed (aesthetical purpose only), oiled an waxed. The Stringholes are cut in crescent shape to form lips which cover the strings, so your ammo won't ever touch your strings causing abrasion.
I uncorded the strings at the pouch (finger-string) and the release end and fixed them again with waxed hemp to create joints in the otherwise unflexible flax rope. Several retries were necessary to create the right angle but I'm very satisfied with the resulting "pistol grip".