I never said slingshot. I said sling. There's a difference. And yes, 30+ damage on 60+ body armour is perfectly acceptable to me for a sling considering there is evidence they were able to crack and dent helmets in ancient warfare. There is even evidence of their usage against the conquistadors of Spain by the Mesoamerica people and they describe the velocity of the slingstone as being enough to kill a horse.
Dude, stop using heavy drugs please. You are not adequate. Really, no offense. I was talking about body armor and you shared your ideas about cracking helmets with sling and stone. Wooden or bronze helmet BIG MAYBE.
You wanna try to do any damage with your sling on brass lamellar over mail with sling? Do you even have idea what is it? Or brigandine over mail? Or scale vest over gambeson, brigandine over hauberk, heavy scale armor over mail hauberk? I will not even feel your stone wearing any of it, not saying about any damage. So your "30+ damage on 60+ body armour is perfectly acceptable to me" is beyond stupidity. I'm sure 80 piercing penetration on a hunting bow is normal for you as well. Woodland longbow with heavy bodkin-point arrows could SOMETIMES penetrate legs, arms or shoulder armor. Here is some historical facts for you:
The Alexiad about the Normans of Bohemond during the latter’s campaign in Greece:
For he knew that the Franks were difficult to wound, or rather, practically invulnerable, because of their breastplates and coats of mail. Therefore he considered shooting at them useless and quite senseless. For the Frankish weapon of defence is this coat of mail, ring plaited into ring,and the iron fabric is such excellent iron that it repels arrows and keeps the wearer's skin unhurt.
Jean de Joinville, describing an incident with Walter of Chatillon during the Seventh Crusade:
..and whilst the Turks were fleeing before him, they (who shoot as well backwards as forwards) would cover him with darts. When he had driven them out of the village, he would pick out the darts that were sticking all over him; and put on his coat-of-arms again... Then, turning round, and seeing that the Turks had come in at the other end of the street, he would charge them again, sword in hand, and drive them out. And this he did about three times in the manner I have described.
Odo of Deuil writing about King Louis VII in an engagement during the 2nd Crusade:
The enemy climbed after, in order to capture him, and the more distant rabble shot arrows at him. But by the will of God his armour protected him from the arrows.
During the 3rd Crusade, Bahā'al-Dīn, Saladin's biographer, wrote that the crusaders infantry there:
...drawn up in front of the cavalry, stood firm as a wall, and every foot-soldier wore a vest of thick felt and a coat of mail so dense and strong that our arrows made no impression on them... I saw some with from one to ten arrows sticking in them, and still advancing at their ordinary pace without leaving the ranks
Galbert of Bruges describing the performance of an exceptional archer called Benkin, during a siege in Flanders in 1127:
And when he [Benkin] was aiming at the besiegers, his drawing on the bow was identified by everyone because he would either cause grave injury to the unarmored or put to flight those who were armored, whom his shots stupefied and stunned, even if they did not wound
During the Battle of Nicaea (1097), Albert of Aix wrote:
Walter the Penniless fell, pierced by seven arrows which had penetrated his coat of mail.
During the Battle of Acre (1291), William de Beaujeu, Master of the Temple, was accused of cowardice when he retreated from the fighting. He lifted up his arm and replied:
Seigneurs, I can do no more, for I am dead; see the wound.
An arrow had pierced him through the mail beneath his armpit—only the fletches were visible
Gerald of Wales, writing in 1137 about a skirmish between the Welsh and the Normans
A knight of William de Braose was hit by one (arrow) which went through the skirt of his hauberk, his mail hose, his thigh, and then through the leather and wood of his saddle into his horse; when he swerved round, another arrow pinned him in the same way as the other leg
So in regards to mail armor, it seemed that in general the answer to the question is MOSTLY NO. Exceptionally powerful arrows striking at good angles might be expected to penetrate from time to time
And I can see you are a big expert in Spanish conquistadors vs Aztecs battles. Bet you saw somebody killing horse with sling yourself. Yes common horse in a head or temple with big stone probably. Now try to do same with fully armored one.