experience-opinions:
Like Zackary, I have an Ishapore, I've stuck with Korean surplus and it's been good. Haven't shot steel from it.
I also have a C308, and have shot both. Seems like the Korean surplus is a bit hotter than the Red Army and Tula, the question I'd have with the Ishapore is more about how it likes the cases.
I have some Armscor 308 I got before the panic, "loose rds" from broken boxes, that was sold cheap in ziplocs by Lucky Gunner I believe. I contacted Armscor and asked about it- they sell both 7.62 NATO and 308. They responded and told me they use the same cases for both.
I also have some Magtech 7.62 NATO in the 50 rd boxes from before this started.
I shoot both in the Ishapore.
For the C308, it runs perfectly with the steel and beats the cases up, so I buy cheap steel and use it in that.
I don't know specifically about the Turkish 7.62 NATO, but I can tell you this: I've got Turkish 9mm, and it's loaded smoking hot, even compared to German NATO overruns.