"I K" is Igman Zavod, Konjic, Yugoslavia,I don't know where the term mildly corrosive come from,corrosive is corrosive. If you don't clean your rifle it's going to rust,so clean after your done shooting.
As far as the accuracy goes,your ability and your rifle/ammo will determine that,shoot some of what you have and see if there is a difference,there is no magic ammo. The Yugo ammo is going to cost you about 19.8 cents a rd. and the B/W about 22 cent each.