SGAmmo sells igman ammo and claims that it is boxer primer brass 7.62x39. If you want to reload this caliber, it sounds like a good source of boxer primer size cases.

Steel cases are economical, but this ammo’s factory fresh brass cases promote cleaner overall performance. Better yet, they are perfect for handloading! Igman loads Boxer primers that don’t produce any corrosive residues on ignition, and they seal them against harmful water infiltration.