vashu1 wrote on Jun 19
th, 2019 at 9:03pm:
TheJackinati wrote on Jun 19
th, 2019 at 3:01pm:
With the very thin Dyneema strands
Hm. Here just a rope is used for record throw
http://slinging.org/forum/YaBB.pl?num=1117439014Cross-section of 30 mm stone would be 700 mm^2, 1 meter long double rope with 4-5 mm would be 8-10,000 mm^2 - order of magnitude more(and most of rope moves slower than ball).
I calculated loss of speed for a ball on first meter of flight with
https://vashu11.livejournal.com/965.html and got
Cd=0.483325 Distance: 0.0(0.0 ya) Speed: 100.0(328.0 ft/s) Energy: 255.0 Height=1.0
Cd=0.483249960568 Distance: 1.0(1.0 ya) Speed: 100.0(326.0 ft/s) Energy: 253.0 Height=2.0
Cd=0.483174939635 Distance: 2.0(2.0 ya) Speed: 99.0(325.0 ft/s) Energy: 250.0 Height=2.0
Cd=0.483099945407 Distance: 3.0(3.0 ya) Speed: 99.0(323.0 ft/s) Energy: 248.0 Height=3.0
Cd=0.483025618365 Distance: 4.0(4.0 ya) Speed: 98.0(322.0 ft/s) Energy: 246.0 Height=3.0
Cd=0.482951322674 Distance: 5.0(5.0 ya) Speed: 98.0(320.0 ft/s) Energy: 243.0 Height=4.0
Cd=0.482877687411 Distance: 6.0(7.0 ya) Speed: 97.0(319.0 ft/s) Energy: 241.0 Height=4.0
Cd=0.482804087943 Distance: 7.0(8.0 ya) Speed: 97.0(317.0 ft/s) Energy: 239.0 Height=5.0
Cd=0.482731142158 Distance: 8.0(9.0 ya) Speed: 96.0(316.0 ft/s) Energy: 236.0 Height=6.0
Cd=0.482654895462 Distance: 9.0(10.0 ya) Speed: 96.0(314.0 ft/s) Energy: 234.0 Height=6.0
Cd=0.482576856842 Distance: 10.0(11.0 ya) Speed: 95.0(313.0 ft/s) Energy: 232.0 Height=7.0
so we lose 5 m/s per first 10 meter.
From that I feel difference between rope sling and modern one would be 10, 20% at most.
I find it quite unlikely that
stones would reach that velocity, at best with a very modern sling, you could probably achieve ~70 m/s throws at max. This would be the upper-limit to what Ancient slingers equipped with lead glandes would have theoretically achieved.
(In the Annabasis for example it cites a range of lead-equipped Rhodian slingers as being around 400 metres, roughly double that of the Persian slingers using fist-sized stones, and largely outranging the Persian archers)
When I was talking about it being possible to achieve 100 m/s throws with a long Dacron-fibre sling, I mean it in reference to Volound's ~52 gram lead projectiles, which are tear-drop shaped airfoils. These are generally being launched from a sling that is probably over two metres in length with a sling that weights around 3 grams.
Also, concerning Borovsky's report, it is probably the best source available yet concerning sling performance. That said I feel that the energy reports are more accurate concerning lower-to-middling range levels of slinging. For example, the stones of 150-200 grams largely maxed out at 30 m/s, Yet an expert like Luis Pons Livermore has been chronographed throwing a 200 gram stone at 52 m/s (Over 200 J), and is known to consistently throw rocks of around ~150 grams at velocities approaching 50 m/s (~180J) even with a fairly short sling (Watermelon from 25 metres video).
But, In general to the answer to your question concerning the maximum energy/speed of a sling missile below 100 g... You'd almost certainly be looking at someone with a ultra high-tech carbon-nanotube fibre sling launching a Osmium, Iridium, Depleted Uranium or Tungsten projectile.
But, until those future slinging mavericks yet-to-be-born arrive, A *lead* projectile is probably going to offer you the most power and range in a 100 gram or less package, which was probably true for the Ancients as well. Using a 42 gram glande from standing with my favourite Jute sling, I can easily reach 200+ metres.
**Unless you want to sling something like Gold, DU or Tungsten, All of which are either extremely expensive, poisonous or very hard to work with... or all three.