Did you know that during World War I the German army (along with other countries, actually) issued steel plate armor as protection for troops? As many as half a million sets of this "sappenpanzer" or "grabenpanzer" armor were made during the war. It was issued to machine gunners and sentries; troops whose duties made them particularly vulnerable targets.
We found some reproductions of the armor for sale, and IMA (International Military Antiques) kindly provided us with a set to do some ballistic testing on. We started by having it analyzed by a metallurgical testing lab to determine composition and strength (so we could have an accurate comparison to the original armor) and then set about shooting it up with everything from .32ACP to explosive 7.62x54R PZ.