Browing the British Museum collection online, found this "sling bullet"— 500 g ! From Athens, and in Latin. So could be from the Roman army's operations in 86 BCE, which left some big bullets of ca. 120 g. THis is an outlier. Catapult shot ? Staff sling ?
https://www.britishmuseum.org/collection/object/G_1865-0720-106

Here's Archaic Arms throwing stones that heavy with a sling:

https://www.youtube.com/watch?v=kpcFYMB8Owg

Agree with Rhonan.  You can definitely do that weight with a normal sling.  In the Sling vs Shield video I did, the largest stone was 499g.  And that was just straight up in the air to feel the impact when it hit the shield.  The heaviest stone I've ever used was 3,273g.  That was using a two handed technique though.  Basically a sacrifice of range for a much greater impact force.

All that said, the 500g glande could have definitely been made for some other purpose or method of launching it.

Yeah a 500g glande is certainly feasible to throw via a sling, both now (as the amazing AA has proved) and historically.
Projectiles of such mass would've likely only been used from higher ground - perhaps finding the most service in ambushes from atop cliffs or hills.

Otherwise, I imagine a ballista could've shot it, though I presume its ovoid shape wouldn't lend itself too well to such a use.

It's not that big an object, 7.5 cm, ie,. smaller than a small egg. But it must feel like pure energy in the pouch

Thearos wrote on Sep 8^th, 2025 at 1:05am:

7.5 cm, ie,. smaller than a small egg

You get different sized eggs than I do.  ;D

You're absolutely right though.  Definitely a manageable size!