Since I've recently experimented creating slings with a bunch of different cord and pouch materials, I decided I should do a direct comparison of the effect of torsion on all of those different material combinations.

For anyone not familiar with this concept, I would highly recommend watching Acroballistics video on it: https://www.youtube.com/watch?v=vOuRwrfA7GQ

TL;DR you generally want more resistance against torsion so that you have more control over release angle and so that the cords don't tangle while the sling rotates.

So I took videos of a bunch of different cord and pouch materials to see how they compare and synced them side-by-side into the same frame. See the gifs at the bottom for the final results!

I froze the frame for each sling once it stabilized, so the gifs overall are as long as the longest sling took to stabilize. Also, I didn't realize how badly the grass background was going to interfere until after I had taken all the footage, sorry about that. They're also hosted on my home server(too big for giphy), so they may load a little slowly.

The basic methodology was to put a tennis ball and a baseball into each sling, rotate it 180 degrees so there is a single twist in the cords, then simply let go. Both are standard sizes and weights: 56g for the tennis ball and 143g for the baseball. All slings are about the same length, 28 inches give or take an inch. Retention loop was on my ring finger for these tests(more on that below).

Here are the different types of slings involved. I made variations of most with 6mm, 4mm and 2mm dyneema as well as 550, 275 and 90 paracord.

• Traditional balearic braided sisal
• Practical Paracord Smiling Sling (custom braid design of a few types of paracord)
• 2-inch webbing seatbelt slings with a nail knot transition to the cords, which makes for a very stiff pouch transition (see Mersa's build video here: https://www.youtube.com/watch?v=-EBfUItUJFM)
• 1-inch webbing overlapped pouch seatbelt sling with grommets connection to the cords instead of the nail knot, which makes for a much more flexible pouch transition
• Spaghetti Slings - I'm using this as a general term for my two similar sling designs that use one continuous cord with a pouch made of the same cord so there is little or no pouch transition. Spliced dyneema version here and paracord version with sheet bends here.

A couple of these are essentially duplicates because I wanted to see if the pouch or pouch connection(nail knot seatbelt vs grommets vs sheet bend vs dyneema splice) had much of an effect; it didn't.

Some notes on the results:

• As expected, both braided slings performed very well.
• Sisal settles super fast and almost hit my fingers as I was releasing the twist. There is a very small amount of kickback from the untwist before it settles.
• The smiling sling settles in nearly the same amount of time as the sisal, but overall a little more slowly, so it didn't have any kickback it needed to recover from.
• 2mm dyneema settles in about the same time as 550 paracord(which is 4mm diameter) at about a third the weight.
• 275 paracord is 2mm in diameter as well, but performs much worse than 2mm dyneema.
• Dyneema that has been rolled flat doesn't seem to perform any differently than stock round dyneema.

And some subjective notes about using the slings:

• With balearic-style windup and throw, I couldn't get 2mm dyneema to tangle with a baseball, which was a little surprising to me. Although as I noted above, I keep the retention loop on my ring finger. With the retention loop on my middle finger, there was some tangling starting to happen with the baseball and the 2mm dyneema. Although for exactly this reason, I wouldn't recommend using your middle finger for single-strand slings - use your ring or pinky. They're simply too wobbly without enough distance between release and retention cords.
• In about a thousand throws I've never had the 2mm dyneema on my ring finger tangle with a tennis ball, and I was able to get a very consistent rifle spiral release from the first few throws.
• 275 paracord would tangle with a baseball quite easily even on my ring finger, and would just barely tangle with a tennis ball.
• Anything above 275 did not tangle at all with either the tennis ball or baseball(on my ring finger).
• On a somewhat related note, all paracord does have the problem of the internal cord getting permanently twisted relative to the outer sheath layer(over time) which will cause strange twisting and release problems even if it doesn't feel like it is tangling during windup. Primarily for this reason(although also for weight and durability) I would not recommend paracord at all for single-strand slings. Dyneema is simply superior in every way.

Baseball:


Tennis Ball:

erricrice wrote on Oct 6^th, 2024 at 10:43pm:

I haven't (knowingly) run into this problem, or heard of it.  Is there a certain sling configuration that's needed?  For example, the majority of single strand slings I've made were done with a leather pouch.  If there's a knot at one end to attach the pouch, and a knot at the other end as a release knot or finger loop, I'm not sure how the core strands would twist.  Just curious.

joe_meadmaker wrote on Oct 9^th, 2024 at 9:11pm:


Any single-strand sling using mil-spec or 550 paracord(or any cord other with separate sheathing) will run into this eventually. You can see some examples in Acro's video here: https://youtu.be/rKbaOivX85w?t=263, but I've experienced the same myself.

Even if you have knots as both ends, you can have twisting in the middle between the knots that causes issues. The friction between the internal cord and the outer sheathing will prevent it from "fixing" that twist on its own, and you have to very carefully(and slowly) pinch the cord and run your fingers all the way down it to untwist. And at a certain point, I've found you simply can't untwist it fully straight anymore. I think that part might be due to differences in stretching between the sheath and internal cord due to differences in force applied at different points of the throw.

Another symptom is "lumpy" paracord. Have you ever had one of your strands get lumpy? That's imbalanced twisting/stretching between the inner and outer cords.

As an experiment, you can try this: twist up your paracord a bunch by hand, using some force to make sure that you're making it past the friction between the inner and outer cords. Then, without trying to straighten it, simply dangle the sling by one end and see where it "settles" with just gravity. It certainly won't be in the orientation where it should be. Then, pinch the cord and run your fingers all the way down to straighten it out(you might also need to grind your fingers back and forth a bit to make sure it's fully straight). You'll see the pouch dance and spin as the two cords realign. Now imagine that effect over hundreds of throws, especially if you are not fixing it after every throw.

For me, this happened in the hundreds to thousand throw range(with tennis balls), so yes if you're slinging rocks this may be a non-issue as the cord would probably fray and break long before that point.

I gotcha.  Yeah, I haven't run into many problems with that personally.  The vast majority of my single strand paracord slinging has been with ice balls.  Very little friction, dragging, etc.  I would imagine that's a big part of why I haven't really had this type of problem.

I would still recommend paracord to people as a cord material.  Readily available, cheap, and easy to work with.  There is the caveat that longevity can be a downside.  I would completely agree that it should be viewed as a cordage that will need to be replaced as it wears out, and not something that's going to last for years and years with heavy use.

Another thing I'd add is that all paracord isn't created equal.  Using 550 as an example (because that's what I've used most), I've had cord where the outer sheath was soft and very cloth-like.  I've also had stuff that was very synthetic feeling and much stiffer.  I definitely prefer the latter.  It was always more resistive to twisting.

And sorry, don't mean to turn this topic into a paracord debate. 

I do wonder if you would have had more success with a stiffer version of paracord.  Here's a little comparison.  The black cord in the attached image is able to hold itself out almost horizontal to the floor with 7 inches of cord.  The second image is a much floppier paracord.  That version is only 6 inches being held out, and it's not even close to retaining the position.

If you are ever in the market for paracord, the black one is from these guys: https://atwoodrope.com/collections/paracord/products/550-x-100ft-paracord-black.  Although it's definitely still paracord, not any kind of magical cordage like dyneema.

Just a note for fun !
Once upon a time I was sitting under a parachute being taught self defence techniques.
The parachute was 1950s vintage and almost certainly ex m.o.d. stock.
I cut off a piece of one of the cords. It passed Joe droop test at about 9inches, it had a rough texture, was an off white, reddy grey colour, and I am guessing was mainly nylon.
I have seen nothing like it, before or since.
On that basis, I am happy to state there is nothing (I have seen) available on ebay, amazon or from any uk commercial rope supplier which matches it.
Perhaps someone who has parachuted recently could enlighten us on current parachute cord. ?
And, I think the simple get out is - what we buy as paracord is genuine imitation parachute cord.
Perhaps this is a new thread ......
😁👍

Hey enjoy Ibiza! Wish I could come this year, but just didn't have quite enough time to prepare. I'll be there next year for sure!