Armor Penetration and Armor resistance.

[Sean Manning]

2mm of work-hardened bronze could easily withstand 120J from a javelin. This is not enough to stop a modern Olympic javelin even at a fair distance but ancient javelins would have more trouble. However, many cuirasses seem to have been closer to 1mm in thickness. This is enough to stop most arrows but not thrown javelins (single-handed spear thrusts and sword stabs have no chance at all). IMO the growing prevalence of body armour at the end of the bronze age caused the bow to be discarded in favour of javelins.

Dan, I have heard you say a few times that javelins have better armour penetration than arrows or spear thrusts. Why do you think this? It sounds reasonable, but I don't recall seeing any evidence other than the surprisingly high figures for energy Paulus presents. It seems to me that spear throwers who could take a run up (skirmishers or a howling warband of Franks, say) would be much more effective than those who could not (Romans receiving a charge, or a Germanic shield wall).