I've done this a few times. Take 5 or 10 tennis balls and drill a 5mm hole in them. Then take some thongs or cord (the same length you sling with) and tie a knot on both ends. Put the one knot through the hole in the ball.

Now go practice slinging. Wind up like you normally do and release. This is a pretty good way of practicing accuracy. Fun, no danger of killing the neighbors or breaking windows and you can use them again and again.

Anyone else ever tried this?

are you hanging on to the ball when you throw? sounds like it might come back at you. lol.

Can you upload a photo or a drawing of this device? :-?

It's a "bola perdida" also known as a slungshot or a ball with a string coming out of it. You hold the end of the string and use it to twirl the ball and just let go to throw the ball. Similar to slinging, but not exactly the same. Why don't you just sling the tennis balls, though?

I agree with Masi. There's no real point in making a lot of these devices when you can merely sling tennis balls unmodified. The attached  cord adds significantly to the drag and reduces the already fairly poor performance of the bare tennis ball.

Tennis balls are virtually impossible to sling more than 80 m and lose most of their velocity within the first 20m or so which makes them very safe. I sling them a lot and have never had any trouble even in relatively crowded public parks.

Yeah I sling tennis balls up to around 20 yards and they will absolutly really hurt if you get hit by one but it won't really do any damage and it's kinda like using ankle weights how if you can sling well with tennis balls you'll probably sling great with rocks.

 I practice a lot with tennis balls.  You can develop accuracy and perfect your stroke in relative safety.  Developing velocity with a lighter projectile frees you from the trap of depending on weight and density to generate power.  Every turn, twist and shift in your stroke, with a lighter projectile,  becomes cleaner and more efficient enabling you to deliver killer power and accuracy.  And as an added bonus for when TSHTF, you can fill your tennis balls with sand and create what I like to call "The Flying BlackJack".  It's not as dangerous as "The Flying Gilloutine", it only "feels" like your head is being taken off.  Remember speed is fine, distance is impressive, but you'll never miss hard enough to kill a rabbit.  Accuracy is final.  

I have tied this and about everything else.  I find that releasing the full weight of a projectile which is held by one cord is really quite different than releasing a sling in which your release cord is only carrying half the weight of the projectile.  It makes a difference on where you impact and on the feel of the whole apparatus.  But it's worth practicing if that's what you have access to.  I think a simple bola is a superior hunting tool for small game to a sling and that has the same feel.    

Tennis ball practice is alas, something I was reduced to for a long time.  I've also done t-balls.  No-longer in that situation, but if it's the best you've got then go for it.  They are safe but I think their size to weight ratio makes them produce a lot of drag while in the sling and changes the shots and feel of the sling a little.  

If I were practicing with tennis balls, rather than tying strings to them, I'd just make a sling by knotting some cotton clothes line cord into a 3 strand cradle.  It takes just 3 minutes to make sling that way and you can size the cradle to hold the balls perfectly.  I think there are directions for this type of sling at slinging.org.  

 

I have found that after a lot of slinging with tennis and other balls its fortunately just a small number of practice shots that is needed to adjust to stones (real ammo, I find i`m more accurate with stones after a little practice than I was with the balls).
So I say it`s at least better to practice with second class ammo than not practice at all.
timann

Mea Maxima Culpa !!!
I think i missed my own point.

I meant that i used this sytem to learn where MY release point is. I wind up and sling at a target 150 x 70cm from 10meters away until i hit it with 80+% accuracy.

This gives me my "natural" release point.

From there i practice with a sling and (uniform) ammo and gradually increase distance.

Does this clarify to some extent?? I don't get my understanding or concepts over in writing as well as i do in practice. Apologies.

P.S -I hit an 8" pine tree trunk from 30m away with better than average (+50%)accuracy today. I was n't really trying. Just slinging for shits and giggles while taking a smoke break.

GM, It sounds like your technique paid off.  I know a lot of guys that practice with light ammo. And I think it's true that it only takes a couple of throws to readjust with live ammo.  I also do a drill where I throw 5 times with an empty sling, watching the placement of the release cord and then sling a tennis ball.  It greatly improves accuracy.  People don't understand that the "Inner Self" doesn't know or care about concepts such as speed, weight, strength, power.  If you practice something smoothly and correctly, speed, balance, accuracy and power manifest as by products.