[kronckew]

...and they used lead water pipes, some suspect the effects of lead poisoning is a contributing reason for the decline and 'fall' of the western empire.

many slingers cast their own shot from lead in holes poked in a convenient clay surface in holes poked in it with their thumbs, cast shot even can show the thumbnails. (as below)

slingers could (and can) propel lead shot at speeds that provided penetrative bone destroying wounds more like modern-ish musketry, not like someone throwing stones that bounce off. the toxicity is not a factor, compared to the sheer physical damage. lead bullets are still often left alone and not removed if not near vital structures as they get encysted - walled off - by the body so lead absorption is minimal. acidic beverages in chalices however produce nice easily absorbed lead salts and may be why some emperors were a bit mad.

like the atlatl, slings can still provide lethality, and they are cheap and easy to make. just because it's ancient tech doesn't mean it's not effective within it's range.

heck, col. churchill* even used his longbow with noted effect in ww2, and special forces still have crossbows available for special purposes.

*- mad jack churchill even went ashore from his landing craft, claymore in hand, followed by a piper, he captured a german unit with just his sword, one at a time.