Bikonische projectiles are a man stopper.
 
They have this form because they can be better shot with a divided "letter".
Their effect is based on shock. They penetrate no armament. Balls penetrate armaments. Findings book this in kalkriese.
 

I agree with Jlasud, pleasure balls seem not to be the best for distance slinging indeed, but for sure they give much better (whatever that means) penetration instead, and require rather more accuracy than power Anyway I think I can see what Jaegoor means.
 
Back to the topic, Jlasud, I am glad to hear about your new good experience with lead projectiles and about the great result. It doesn't surprise me I used to sling them some years ago and if I remember correctly they went rather noiseless from my position, of course, only when were released cleanly. Probably it is a matter of surroundings or my maybe ears. For example, I remember that the most of stones we slung together from the cliff were noiseless, despite of a few incorrectly released "buzzy" ones. Anyway I can imagine that glandes can be audible when slung over a quiet lake.
 
When it comes to the strange splashes, I also think that they were caused by a shoal of small fishes. I have observed similar thing, but splashes weren't so numerous like in your case - just a one, two or so.

Quote from Jaegoor on Jun 12^th, 2012, 2:15pm:

I agree,the biconicals can be a man stopper.
I also agree that they stay better in the split (divided) pouch "letter".
I somewhat agree that their effect is based on shock,although they're main damage would be the penetration of the body.
That they penetrate no armament,pretty much agreed.Plate,mail,leather armour,shields helmets,would all stop,ricochet a "light" lead glande.  
But with "Balls penetrate armament" i highly disagree. they have less penetration against anything,than biconical ones,and don't fly as far.
Historical lead balls as sling ammo are almost none existant,Thearos probably could say more about them,but i've searched a lot about historical glandes and never saw one single piece.

I agree, and I suppose that while a sphere leave a round hole in a skull, a biconical would leave a more jagged fracture.
Plus that would explain why we've found both rounded and biconical bullets in the same context (South-Italian excavation, Neolithic).
Greetings,
Mauro.

Mauro them can be also proved here in the north by Germany. And not only from the Stone Age.

Of course round shot can cause damage..i just wrote,that biconicals will have better penetration. And i agree that a heavy round stone will cause more damage to an armoured opponent ,than a light,biconical lead gland will.But this has to do with the mass of the projectile. Given the same weight,a biconical slung rifled,will make a bigger dent on plate as a round one.

Congratulations Jlasud on a very long throws!