Flak Jacket: Description says "Sturdy and effective against most small caliber rounds." However flak jackets were designed to protect against fragmentation from high explosives and other low-velocity projectiles. They provided little protection against bullets, even those fired from pistols.
Chain Mail: Description says "a flexible yet resilient barrier capable of protecting the wearer against blunt force trauma. This form of armor was most commonly used by European warriors between 300 BC - 1500 AD" However it was in common military use up until 16th century AD in Europe. In addition chainmail provided minimal protection from blunt force trauma, it mainly protected the wearer from slashing weapons.
Chain Mail: Description says "a flexible yet resilient barrier capable of protecting the wearer against blunt force trauma. This form of armor was most commonly used by European warriors between 300 BC - 1500 AD" However it was in common military use up until 16th century AD in Europe. In addition chainmail provided minimal protection from blunt force trauma, it mainly protected the wearer from slashing weapons.