Quote Originally Posted by PhoenixPhyre View Post
[2] Bronze is an alloy of metals with certain aspects, which are found together in nature somewhat more frequently than copper and tin are on Earth. But the basic idea and the properties are close enough for government work.
Bronze is an alloy of copper and something else. Tin isn't the only potential partner to the copper, one used earlier was arsenic. That's where the myths of the "lame smith" come from, because working with arsenic is very unhealthy. So you've got potential license with what the other material(s) are.

Quote Originally Posted by Pauly View Post
The Incas had fairly advanced metallurgy. The primary weapon was the sling, and the best armors against sling shots are ones that can take the impact and spread it out and slow it down. i.e. quilted armor. There are Spanish records from the conquest and revolutions that report Inca slingers being able to kill Spaniards with iron helmets through headshots. The primary sidearm was a mace. Bronze armor doesnít defend that well against maces and slings so there is a good chance the Incas just didnít consider bronze armor worth developing. They did have some ceremonial bronze armor, but that was so thin that it cannot have been intended for warfare.
Again, there's bronze and there's bronze. Were the Incas up to the Chinese level of skill with bronze? Greeks and others fought very capable slingers like the Ligurians and Balearics (who used lead bullets, rather than pebbles or stones), and didn't seem to consider bronze armour insufficient.