The key things I have found teaching sling classes to groups (four groups so far) are:

Get your hand back, as far back as you can. Those last twelve inches or so can make the difference between a mild delivery and a proper whipping accelerating shot. Before you throw, think 'Back!'

Rotate with the wrist only, like stirring a cup of tea. It needs hardly any effort and only enough speed to keep the sling horizontal. Any more than that gives you less time and pulls your hand around unnecessarily. If you rotate with the whole forearm, from the elbow, then your hand will creep forward and you will lose power.

Start your throw as the sling crosses in front of you. Dont wait for it swing behind you so you have something to 'throw against', this is too late and will only give you a mild delivery. You want your hand to be moving while the sling is 'blind' on the backswing, you will not feel any reaction from the sling at first. You want to get a sudden 'kick in the pouch', a  'surprised' reaction from the sling that yanks back against your throw. This is where the energy transfer happens and the pouch accelerates to high velocity in a fraction of a second.    

Start with your weight on your back foot, with that foot pointing 90 degrees away from the line of aim. This will set up your body sideways on to the target with your throwing shoulder as far back as possible. When you throw, let your weight flow forward onto your front foot, come up of the toe of your back foot a little but you dont need to do more than that for a Helicopter.

I think one of the reasons I start the throw wrong / too late is that (living in a town) I don't have much occasion for continuous slinging, so a lot of what I do is dry-firing. Aussie pointed out to me a long time ago that dry firing is good for one thing (practising crisp release-- and I need that to, maybe 2% of my shots fouled on release cord), but actually gives bad habits as for sling placement.

Thearos wrote on Sep 7^th, 2011 at 8:11pm:


I sling tennis balls for the very same reason ie. living in a city. I have never had anyone ever complain when I sling in public sports parks (not gardens) and I sling a lot! TB's are relatively poor sling ammo because they're a bit light and don't go far. But in public places that can be an advantage and you don't have to go too far to retrieve them.

Only too happy to send you one or more of my slings which are optimised for slinging tennis balls