Yes, of course.
Here is a scholarly bibliography:
C. BRÉLAZ, P. DUCREY, Une grappe de balles de fronde en plomb à Érétrie. La technique de fabrication des projectiles et l'usage de la fronde en Grèce ancienne, Antike Kunst 46, 2003, 99-113; W. VISCHER, Antike Schleudergeschosse, in Kleine Schriften, vol. 2, 1877, 240-84; G. FOUGÈRES, s.v. glans, in Ch. DAREMBERG, E. SAGLIO, Dictionnaire des antiquités grecques et romaines, 1877-1919, vol. F-G, 1608-11; M. GUARDUCCI, Epigrafia greca, vol. 2, 1969, 516-24; C. FOSS, A Bullet of Tissaphernes, JHS 95, 1975, 25-30, surtout 28 n. 19; idem, Greek Sling Bullets in Oxford, Arch. Rep. 21, 1974-5, 40-4; W. K. PRITCHETT, Greek State at War vol. 5, 1991, 43-53; A. CHANIOTIS, War in the Hellenistic World, 2005, 95; C. BRÉLAZ, Des balles de fronde à Daskyléion: armes de guerre ou armes de chasse ?, Anatolia Antiqua 15, 2007, 71-82;
Some ancient sources:
in Greek, Xen. Anab. 3.3.16-18, 3.4.16-17 (discussed many many times in this forum-- and indeed in the thread I referred to).
in Latin, e.g. Aen. 9.587; Ovide, Met. 2.727 (which supposes that Balearic slingers used lead in Roman times)
Many examples found archaeologically. E.g. on the island of Rhodes. Or near Athens. References in Pritchett, below.
For starters, W. K. Pritchett's book on war in ancient Greece, vol. 5. It's on google books
http://books.google.co.uk/books?id=z1kbyWNJIt0C&pg=PA1&dq=pritchett+greek+state+...(also has evidence for darts)