Awhile ago I made this sling. It is made out of cheap cordage with 2 straps of (in this case, fake) leather from an old belt.
Holes are punched with a regular paper hole puncher. The design is very similar to the Aussie pouch but without having the two straps glued together at the ends.
After testing out multiple sling designs I believe this is the most versatile and durable sling design of all.
This design slings small rocks, big rocks, uneven rocks, very slippery and smooth rocks, spherical clay balls, clay and lead glandes, tennis balls, golf balls and snowballs all equally well.
Most of my other slings have a compromise. My regular split pouch slings don't sling golf balls or spherical ammo (except tennisballs). My braided split pouch slings don't sling incredibly smooth rocks well or sling small rocks at all. My woven closed pouch slings often have pouches that are a bit too small and tend to fail with big smooth rocks and definitely can't sling tennis balls, and weaving the pouches takes a lot of time and rope. My flat leather pouch sling doesn't hold golf balls or tennis balls properly. And they all suck slinging snowballs, except this one. Aside from that, they all need more care and time when placing the ammo in the pouch. With this design you drop it in and go
Because the two middle pieces are not glued together, they have inherent adaptability to any ammo. Old belts can be bought at any thrift shop. All it takes is 4 cuts and 4 holes and you have a pouch. Because it's so simple, it can be made in 20 minutes (or less if you don't twist the cords, although I recommend doing so). This is the first sling design with which I am truly confident throwing anything that I come across and have access to in my ammo inventory without having to swap between different slings. Since I built it, it goes everywhere with me.