Some time ago I made a different release sling that David Engvall used too.Today I found that sling and made some special ammo for it.Never tested it,but I would like to compare it with a traditional sling that has the same lenght and ammo.The advantage of this sling I think is that has very little air drag and releases the projectile with lesser friction than a traditional one.Another advantage would be the perfect consistent release.Cons are that it does not spin the projectile,and can only shoot special ammo with a hook.

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Fascinating.  I'd have never thought of that.

Let us know how it goes.

How could you make and not find the time to give it a try. I'd be pretty interested in finding out how it goes.

dork wrote on Dec 9^th, 2010 at 8:07pm:

How could you make and not find the time to give it a try. I'd be pretty interested in finding out how it goes.

I didn't try it because I only made one iron dart with fins on it and I didn't wanted to sling it randomly to lose it.Now that I have some lead ammo cast with hooks made from wire in it,like sinkers, I will try it,and publish the results.

Today I had a great slinging session,and also tested out a few of the lead glans with wire loop using the special release sling.I wasn't impressed as the wire loop was messing up the aerodynamics pretty badly for extreme range shooting,for what it was intended for.I could hear them hissing through the air and couldn't sling them as far as with a regular sling and regular gland of the same dimensions.So this is why David Engvall choose to put fins on his projectiles when he made the World record.He's original setup is much better than the one I made,but anyway it's an interesting concept.

I'm thinking out loud here, but I wonder how a pyramid sinker would work?

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Compared to stones really good,but compared to a nice elongated airfoil shape gland,not so good.And if it was slung from a special sling like this,it would have to flip it's big ass forward and leave it's point in the back.

True.  There's another kind I'm thinking of, but I'm not sure what it's called.  It's like a semi-flattened circle with that same kind of wire tie.  I'm trying to find a picture of it.  That might actually work.  
  I couldn't find what I was looking for, but perhaps bell sinkers like these would work.  They're more aerodynamic and wouldn't have to turn around like the pyramid sinker.

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One of the problems in any of the above setups is that the sinker is moving sideways, not point forward, when it is released. David Engvall's dart had the hook engagement mechanism in the side of the main body so it was flying point forward at all times, with minimum air drag.

It is critical that the projectile be launched correctly oriented as it will NOT automatically self correct and that lovely potentially aerodynamic shape will be wasted; you'd probably be better off with an ordinary ball shaped sinker.

Rat Man wrote on Mar 13^th, 2011 at 5:11pm:

True.  There's another kind I'm thinking of, but I'm not sure what it's called.  It's like a semi-flattened circle with that same kind of wire tie.  I'm trying to find a picture of it.  That might actually work.     I couldn't find what I was looking for, but perhaps bell sinkers like these would work.  They're more aerodynamic and wouldn't have to turn around like the pyramid sinker.

The bell sinkers would be much better than the pyramid and maybe even the one I used because they have their center of mass in front of it's shorter axis,and that helps them orient themselves quicker.The one I used was symmetrical like a rugby ball and that made them spin along their short axis,because the sideway release.

Aussie wrote on Mar 13^th, 2011 at 6:45pm:

One of the problems in any of the above setups is that the sinker is moving sideways, not point forward, when it is released. David Engvall's dart had the hook engagement mechanism in the side of the main body so it was flying point forward at all times, with minimum air drag. It is critical that the projectile be launched correctly oriented as it will NOT automatically self correct and that lovely potentially aerodynamic shape will be wasted; you'd probably be better off with an ordinary ball shaped sinker.

I agree,and know that David Engvall had a hole in the side of his projectile which is much better.With an elongated airfoil shape gland that has it's center of mass much forward than it's half length it would self orient pretty quickly(not like the one I used)but of course this self orienting and sideways release can cost quite a bit of aerodynamics.Anyways I will probably try the original design too just to compare things,but from this experience I don't think that this special sling is better than a nice thin traditional one with a small pouch.When I made this setup,I thought that self orienting will resolve things,and it didn't,at least not until it spin the gland a hundred times around ,and maybe after a 100m flight it did.

if a dart is point heavy then it will self correct.
But either way you're better off launching it in the right orientation.

Curious Aardvark wrote on Mar 14^th, 2011 at 1:21pm:

if a dart is point heavy then it will self correct. But either way you're better off launching it in the right orientation.

This is the case with darts, however it is not so with all elongated projectles. A good dart like Hondero's kestros which he launches with a similar sideways motion, does correct and fly point forward. Nevertheless, it has been my experience that elongated solid projectiles do not self correct, or only to a very, very limited degree. I've experimented with elongated stones, old machinery rollers, batteries, rubbers door stop type tyres, and even a lovely golf-cross ball sent to me by C-A. Of these only the golf-cross ball showed any tendency to self correct. All the other projectiles were perfectly happy to fly sideways, at some odd angle, or even with the long axis vertical. Golf cross balls are very aerodynamic, feature dimples like ordinary golf balls and importantly have a density only marginally higher than water. Lead sinkers have so high a density that at slinging velocities the differences in air pressure over various parts of the sinker's surface are insufficient to cause it to turn.

I am convinced that slung leaden projectiles like the pear shaped sinkers featured above, will never self correct. They must leave the pouch already correctly oriented and spinning about the long axis for gyroscopic stability like bullets from a firearm.