I've seached several posts, including other forums, and cannot seem to find if there is any 5.45 ammo that is NOT steel core.  Some vendors state Wolf as being FMJ, but others also say bi-metal, which I assume means steel?  I've just ordered some Russian surplus (definitely steel core) as well as Silver Bear ("bi-metal"), but want to make sure about the Wolf before spending more $$.

Reason for asking is I'll be attending a carbine course (with a S & W MP R) that will frown on holes in their steel targets  

Thanks!