Whoa! These rusty balls really flatten out from the forces from spinning! They are egg-shaped when I place them in the pouch. I always thought that stones or rigid things flew better than these, but didn't have any evidence for it other than some strange trajectories. The aerodynamics on my particular rusty balls must be terrible! It may change if I didn't throw as hard, they might not flatten out as much. These were an average throw so probably ~35 m/s (~80mph).

Also, this was one of the stiffer balls with  more balloons (10 in this case). The ones that I have that only use 6 balloons flatten out even worse.

This images if taken frame by frame from a movie recorded at 240 fps using my phone.

It would be interesting to compare that to a y-sling with minimal spin.

This is not surprising.  I use around 12 to 15 balloons for one ball.  The diameter of the balloons is also important.  If this is too big, the balls will be too soft

Jaegoor wrote on Dec 17^th, 2020 at 2:21am:


This is good to know. I always wondered how many you used. I will add some balloons. As far as size goes, the balloons I use have to be stretched slightly to go around the first sand balloon.

It is my experience. It might be the construction of the sling too, since my retention cord is kind of stiff. But it comes down to less twisting of the retention cord during release. You can see how my wrist is oriented, and I get a nice clean rifled release. If you go and watch my 1 hour challenge video, I have a similar orientation of the wrist at the moment of release, but often the pouch is oriented strangely, causing it to spin like a top on release. I attribute this to a floppier release cord and a single finger loop. 2 seems to help keep the cord from twisting as much.  Just empirical and anecdotal evidence, nothing concrete to back it up.   

Jaegoor wrote on Dec 17^th, 2020 at 4:17pm:


I also have tried hard to destroy one. I couldn't do it.  A balloon might break, but it is easily fixed.

They are a great slinging innovation. I'm glad I finally got around to trying them, Jaegoor. I'd seen you use them for years, but this is the first year I have actually used them. They are great!

IronGoober wrote on Dec 17^th, 2020 at 5:13pm:


Agree! I love using rusty balls.  I keep 2-3 balloons with me incase the outer one starts to tare.  (out side I can hit sharp rocks ect.)  I love that they don't bounce or roll once they hit something.  Also if you use a bright colored outer balloon they are very easy to find.

I still have a bag of balloons on the side but no sand to put in them. I should get round to that. "I'll get round to it" is one of my most used phrases...