SS109 / M855 and steel don't play nice together , 223 / 556 is hard on steel already without adding a steel penetrater to the mix . Steel damage is all about velocity and point load , small fast bullets = damaged steel .

Those targets in the link above will fail sooner than other designs because of the square corners where the ears are creating stress points and they will crack off .

Go to the vendor section and get hold of Austin at AA targets , he's local and affordable.