There are a LOT of types of 8X57 Mauser ammo out there..
Some, like the German WW2 AP ball is frightening in it's effectiveness..
Even the common 190 grain surplus ball is pretty good, but not in the same class as the U.S. M-2 AP ball
Some description of the headstamp, and the packaging if any would help me to find out more about you ammunition's possible performance against plate.
Meplat.