how do you tell if its yugo? I just got a couple thousand rounds of 8mm super cheap and I have a new JBM chrome barrel. the headstamps are E(primer)K, and the other stamp is just a 59. the 59 has a fatter bullet but it dry cycles fine through my barrel. I checked with a whole belt of each stamp. Complete lockup each time. (sure made my arm tired) I keep seeing that people have problems with the yugo in the JBM barrel and I just want to make sure before I go blasting