Most rotating throwing weapons (throwing knifes, throwing daggers, throwing axes such as Tomahawk or Francisca) share the same problem: They are fine for a trained user at a specific distance, and little good at a shorter or longer distance. The correct window may be as small as between eight and nine metres distance. It sure was difficult to get that right in a stressful combat situation, and even more so during an infantry charge.
This small window is a consequence of having but one sharp edge (axes) or point (knives) that does much damage. If you throw at full power from the wrong distance the rotation may be 30° too much or 30° too little and the edge or point doesn't hit, resulting in little more effect than with a thrown wooden stick.
A possible solution was the South Asian Chakram or Chalikar - a ring with a 360° edge. This introduced a different problem, though - a direct, rather blunt hit would do rather little damage because even though the edge was sharp, the ratio of surface are in contact to momentum wasn't all that impressive. It was nothing like a knife's point or an axehead's edge.
A different solution was pursued in Africa, apparently first in Sudan: Throwing knifes with multiple points and sharp edges, making it much less important by how many degrees the missile rotated before impact. It would usually be nasty unless stopped by a shield or armour.
|A collection of African throwing weapons (c) geni, see here|
The photo shows it; these throwing weapons were mostly suitable for melee as well, not exactly standardised and (in my opinion) rather not optimised. It's almost as if a scary appearance was an important requirement of their design.
There are many names for these African weapons (or munitions), seemingly varying regionally as much as functionally;
Kulbeda, Pinga, Trombash, Shongo, Shango, Kpinga, Sapa ... by now it's likely clear why for once I didn't write the name into the title of the exotic ancient weapons post!
Of course, the widely known Shuriken of Japanese origin with its four or more points and no handle makes it almost entirely irrelevant how much it rotates before impact. The difference is at most between one point penetrating somewhat deep and multiple points doing more shallow penetrations. Shurikens are also more compact, but they have one severe shortcoming: They have no handle unlike throwing axes, those African throwing weapons and so on. The grip can thus be not as firm (limiting power), and there's no substantial lever, since the hand grips the missile very close to its centre of gravity. There's not necessarily a rotaton involved (and thus no rotation energy) in shuriken throws.
In case you don't quite get what I mean here, look at Atlatl and Woomera, two weapons meant to exploit a long lever for more throwing power (see here or here). The Ancient Mediterranean world used small slings attached to javelins for the same purpose.
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Throwing weapons are among the more confusing historical weapons in my opinion, since their range was typically only 9-45 m depending on design (Plumbata possibly more), and the used had to switch to a melee weapon in a few seconds after the throw in order to be ready for melee in time. The throwing motion also fits poorly into the dense formations fo closed order tactics, which makes the great popularity of javelins in the Roman armies even more confusing, and the issue with range sensitivity makes the supposedly well-documented use of Francisca throwing axes by the migration period Franks (during a charge!) almost unbelievable.
The one exception are peltasts in Ancient Greece, especially when facing a relatively rigid phalanx as target. I just don't understand why they used the small slings attached to javelins instead of using a kind of Atlatl that can double as a battle axe with the other business end.
These African throwing weapons required a great smithing effort required and are thus rather confusing as well. Their shapes were also apparently never optimised into one dominant design. Most throwing axes look alike, most throwing knifes look alike, most javelins look alike (save for the possibly overengineed pila), but the Africans never agreed on one dominant design. They're challenging an otherwise widely observable pattern in military (weapons) history.