So, can you sling lead hard enough to melt a gland?
Ancient authors thought so, as quoted on this site in
"The Sling in Literature" by Michael Gillelan:
"It was a common misconception in antiquity, from
Aristotle onward, that bullets propelled by slings
travelled so fast that they became molten. Lucretius
makes this mistake (6.178-179, tr. H.A.J. Munro): "A
leaden ball in whirling through a long course even
melts" (plumbea vero / glans etiam longo cursu
volvenda liquescit), and so does Vergil, Aeneid
9.586-589: The hero Mezentius, putting aside his
spears, with tightened thong whirled thrice around his
head the whirring sling and split his adversary's
forehead with the molten bullet and stretched him out
flat over a great stretch of sand."
Between Heroic Hyperbole and the Slinger's Stretch, who knows where the truth flies. However, observing the deformation that lead glandes undergo upon impact, I believe this represents at least
partial melting.
scale = 1 cm
I whipped a 2 oz lead egg sinker into a concrete
block. Sling only, no hammers or other tricks. It
bounced back 3 meters and was still hot when I picked
it up. It shortened 22% and widened 11% compared to
its unused brothers in my pouch. (I'm thinking
without checking the Latin that Glandes must be
masculine by definition).
Molten Glandes? Could be, Could be.
These Egg Sinkers are available in multiple sizes in fishing tackle departments. Less than 2 oz are too light, over 4 oz are getting pretty heavy. Since Energy = Mass x Velocity squared, you don't want too high of a mass because you really lose energy if you can't keep up a good whipping velocity.
Happy slinging.