There is a posting on Internet saying that I K is Igman - like from Bosnia / Yugoslavia. Is also another posting that it is Berdan primed (not Boxer), and a third posting saying it was corrosive primed - so take that for what it is worth - Internet postings by "somebody", like this one ... I have various years of Hirtenberger 7.62 and also some Portuguese (?) 8x57 - it seems they swapped out Berdan versus Boxer primers (and, therefore the primer pockets / flash holes are different), and corrosive or not corrosive, as years went by,