Wow. That looks it could do some damage. That's a pretty amazing find. Someone needs to recreate it. It would really interesting to see how it moves through the air.

Forgive my ranting. As an archaeologist, I disapprove of private collecting of objects circulating on the market without provenance because they have likely been produced by destructive uncontrolled excavation. That also holds for metal detectorists. (it also produces the collector mentality "since I paid for this, it must be beautiful", "exquiite craftsmanship on this piece", that distorts our knowledge of the past and reduces it to baubles rather than whole societies)

That said, a lot of these sling bullets are found without context anyway

But that said, having them found and sold this way means that we potentially lose a lot of info. For instance, if they were found in caches we might date them; if they're found in places we might relate them to specific campaigns or battles; if plotted on the ground we might relate them to battle tactics (as in the famous find of ugly sling bullets from Vetren, where you can see lead used at very short range and concentrated fire); if they're found in context we can actually say something about production. I.e. the more provenanced examples we have of this "flying saucer" type (which I remember seeing in the literature, perhaps published by Ino Nicolaidou in the 1970s), the better our specific, non-speculative knowledge will be.

There, I've said it. I have posted on this before and apologize, again, for the rant.

Thank you all for the comments!

I studied in the field of Historic Archaeology here in the states, but 2 factors discouraged pursuing a doctorate: I determined that such a career wouldn't be as remunerative as what I do in my spare time, and I learned to my great dismay that the post-doctoral "professionals" couldn't tell the difference between an "Iron Pontil" and an Owen's machine scar on the base of a bottle (among other things), and considering that discarded bottles and jars are of great utility in the dating and interpretation of sites in the USA, such ignorance destroyed whatever faith I might have had left in the education I would receive at that university and I decided to just collect and appreciate all the artifacts I could get my hands on without regard for the nearly universal opinion that only those professionals are qualified enough to handle and interpret the residues of history. I'm certainly not condemning the field or genuinely talented practitioners and I do wish you the best, but have made my decision.

That said, I agree that the destruction of edifices and necropoli (as in Bulgaria) in search of ancient treasures is heartbreaking, but the items I collect are essentially all "everyday" items found by detectorists in woods and fields; not fine ceramics, jewelry or art looted from graves. While theoretically erosive to the potential corpus of archaeological knowledge, unless funding is obtained to turn half of the landmass on earth into an archaeological dig 99.9% of those detected items would remain buried until they completely rotted away.

And fakes are an enormous problem for collectors, though many archaeologists interpret the prevalence of fakes as a buffer against the further looting of archaeological resources, as the money spent on garbage isn't being spent on the authentic items. Essentially all of the "legionary" roman rings, inscribed fibulae, stone seals, figurines and amulets are fakes, and probably 3/4 or more of the stone, bronze and iron artifacts are outright fakes or purposefully misidentified for profit, so I've learned to avoid many dealers and classes of artifact like the plague and develop relationships with honest sources. I do feel sorry for all those getting duped, but at the same time that means there is less competition for the genuine articles. I can't prove anything to y'all but I've been collecting antiques and old coins since age 5, started selling them at 11, and expanded to ancient European items at 14 so over time have developed a pretty solid and nuanced instinct regarding such things.

For those interested in collecting sling bullets, be exceptionally careful of inscribed examples coming from Spain, as there are many forgery workshops there churning out fakes; some more deceptive than others. Do your research and if it "smells fishy" it's best to avoid it. Never implicitly trust the dealer/seller and go by your own "empirically-informed instinct" instead.

Anyway, the "Ino Nicolaidou" lead is a helpful start, thank you! Here is a very interesting bullet from Bulgaria, inscribed with  what I presume to be the bust of a (Corinthian?) helmeted soldier with exaggerated nose-guard, facing left. I haven't found any documented examples of people depicted on bullets so it's quite unusual. 31.43 grams, 29mm long.

yeah would appreaciate it if you could resize them a bit.
800x600 (ish) works best.

If you don't have anything simple to use, scroll to bottom of first post here: http://slinging.org/forum/YaBB.pl?num=1258292684
and download photo resizer.

If you've got a mac - you've got my sympathy, but no clue on resizing programs  

so you think the image on the stone is deliberate and ancient ?
Could just as easily be caused by random breakage.

I can see someone going to the trouble putting bronze blades inside lead - that's serious armour piercing.
But why would you spend hours putting a picture of a soldier on a single sling bullet intended for battle  ?
When that time would be better spent making more sling bullets.

Given that a skilled slinger can easily throw 10 shots a minute. More stones would be more valuable than really pretty ones.

Doesn't make a lot of sense.

Just for clarification, the bullet with the helmeted bust is made out of lead and the design is raised/embossed, so while it may have taken hours to carve the mold it was cast in, casting multitudes of them would have taken no more time than the regular plain bullets.

As I understand, the inscriptions would either convey information that would express the identity of the shooters and their origins or commanders to the enemy forces, or insult/taunt the enemy. I'd suspect that the person depicted expressed some sort of autobiographical information. And yes, they would most certainly have been used in battle.

To further illustrate the casting process (you've read about the cast "trees" of bullets") here is a text-only example showing a very obvious offset casting sprue. I don't know Greek but based on my toying with internet "ancient greek keyboards" and online translations the text on the first side may translate to "Cereal" or a "(Kernel of) Grain" which suggests a taunt of some sort. I could of course be completely wrong and happily invite any corrections or insight. 27.25g, 29mm.

And I'll try to edit the gigantic images with more reasonable ones, don't want to hog bandwidth. 

I have no idea about any perceived advantage, maybe it could be placed in the pouch and released in such a way that the bullet would spin on the same plane as the blades (shuriken style). Maybe the flatter sides would allow for fine-tuning of its placement in the pouch to allow for a football-style spin upon release, whereas the biconical ones would just roll to the center. My skills are lacking in this department so it's all just loose speculation; maybe it's just another example of their lack of familiarity with the principles of aerodynamics.