[Elio Pestana]

Using the holidays as an opportunity, me and my grandfather decided to try and see if we could make ourselves a pair of slings, since none of use had ever actually ever shot one and we have an interest in ancient history and warfare.
However, while we do know how the slings should look like once finished, on the technical side... we're not exactly very aware of what materials we could use (historical or not) or how long these should be.
Would you happen to know of any guides or just general advice for the manufacturing of a sling ?

[Mikko Kuusirati]

Well, first you have to decide whether you want to make them historical or modern, nice looking or just functional. Personally I've made some perfectly nice ones out of leather scraps and paracord - not historical, but they work great and aren't the ugliest things ever.

Tod here shows two very simple and utilitarian designs.

I'd suggest you make something like that to start with. They're quick and easy and cheap, so you can experiment with the dimensions and find what works for you before committing yourself to anything more involved. Once you've figured out roughly how things work, which finger you like the loop around, your preferred technique - see here for a great showcase of several to try out - and how long you like your sling, then you can move on to fancier stuff like braided and woven designs, in natural fibers or modern cords, if you want.

The longer the strings are the more power and thus range you can get in a throw, but after a point you need heavier projectiles to get any benefit from that, and greater length also requires better technique and doesn't allow as much precision. So, as a general thing, short slings are good for short range and precise shots, long slings for long range and powerful shots (with heavy projectiles). The length of the sling also dictates the timing of your swing and release: you have to be quicker about it with shorter slings, while longer ones act at a more leisurely pace even for the same release velocity. At least to start with, I'd recommend something between the length of your arm from thumb to shoulder on the lower end, and from thumb to the opposite shoulder on the upper end. Also, making the strings short enough that the pouch won't touch the ground when you let it hang down by your side can make things a little more conveniently manageable.

Remember that your choice of projectiles dictates the size of the pouch: a solid pouch just needs to be big enough, while a split pouch also has a minimum size of things it will hold. And speaking of projectiles, I wouldn't recommend starting with rocks unless you're way out of sight of anything fragile, like houses; tennis balls or similar can be good, but they tend to bounce around like crazy if they hit anything solid which makes them a pain to retrieve (plus the color stands out against a tennis court but is a real pain to pick out from among green grass). Golf balls fly great, and are cheap if you buy used ones in bulk, but will also make holes in windows and dents in walls (and people!) just like rocks. Beanbags are probably the safest and most convenient thing to start out with. Or really anything about 50-80g in weight, smooth and regular in shape, soft enough not to cause real damage and preferably not very bouncy.

Another consideration when practicing is that a horizontal swing and release (like the "helicopter" or "Greek" styles) makes missed shots deviate mostly to either side, and a vertical release (like the "figure 8" or "overhand" styles) mostly up or down. So if you're worried about hitting something around you, use a vertical release, and if you're more worried about overshooting and hitting something downrange, use a horizontal release.

(Personally, my current favorite sling is a lot like the one used in that second video - split pouch made of two pieces of scrap leather, paracord strings secured with cotton yarn whipping instead of knots; if I hook the pouch around my left thumb and extend the arm out straight to the side, the strings reach exactly to the middle of my right shoulder. I like to have the loop on my middle instead of index finger, it just feels more stable and seems to cause less tangling.)

[Mikko Kuusirati]

Anyway, once you have at least a rough idea of what size of sling you actually want to make...

Here's a photo tutorial for braiding a simple Balearic style split pouch sling - probably the easiest type of braided, woven or plaited sling one can make, very elegant in its simplicity and exactly as effective as any other. These are extremely popular, and for good reason. You can use almost any natural or synthetic cord as long as it's about 1.5-2mm thick and sufficiently pliable but not significantly elastic; IME most soft-ish types of nylon cord are perfectly fine, cotton works well, linen even better, and hemp and sisal work but I tend to find them unpleasantly rough.

And when you want to try something more advanced, here's a whole big thread at Slinging.org of nothing but tutorials and instructions for making and using slings.

PS. Oh, and unless you're already familiar with knot making, you'll want to learn some basics of that! Animated Knots by Grog is my favorite online reference; I tend to use a figure 8 or double overhand knot as a stop on the release cord, constrictor knots to secure the ends of any whipping, and a perfection loop works great for the finger loop on paracord slings.