The AK round has a nice, steep taper to it, which aids in extraction. Not so much for the AR rounds. I think this is why steel works so well in the Rooskie cartridges, even with the lacquer.
“...I think this is why steel works so well in the Rooskie cartridges, ...”
That, and they’re designed from the getski-goeski (nyuk, nyuk, nyuk) to use steel. The extractors are brutally tough.