Ok, that all make sense. Moving forward then to the medieval period and the renaissance era presumably metallurgy had come a long way since the Roman period ?
Steel is I'm guessing the default metal for such an era. Now in the renaissance era we get suits of plate armour that have been 'proofed' against firearms, that is at certain distances they would resist pistol ( and maybe ) musket shot.
This obviously represents a major leap forward from the Roman era. Was this due to better materials ie better grades of steel, or was it due to better metal working and forging techniques ?
Or, and I suspect this the answer, a combination of both of the above ?