Before moving to MN from GA I owned an Izmash built AK (with select fire aka: Go Button) and it never produced any brass that looked like that.
I also owned a HK-91 (also with the Go Button) and it really screwed up the brass, due to the way the chamber seemed to have what I call "flutes", for the lack of having a better term.
I had to sell them, due to my move up here and a pending divorce, in addition to MN not being as friendly as GA was toward guns with Full Auto capabilities. I wish I still owned them