American-made barrels in this case were both button rifled/chrome lined and (one of the American barrels used was) cold hammer forged/chrome lined, which is the same manufacturing process used by Russia and the former soviet bloc countries to make AK barrels. All tested barrels, including the cold hammer forged barrel, showed nearly identical wear patterns and accuracy results- that is to say, all the barrels used with bimetal jacketed bullets were shot out around 6k rounds, to the point of keyholing rounds. A button rifled, chrome-lined barrel used with copper jacketed bullets survived the 10,000 rounds test still producing similar accuracy to the start of the test and showing measurements on a throat gauge indicating that it still had some thousands of rounds of life left, despite the rapid fire abuse. My cold hammer forged SLR-106 barrel hasn't shown signs of keyholing, but accuracy loss is significant and appears consistent with the degradation recorded on the charts in the test. (several of the images are actually multi-image slideshows showing data for multiple ammunition types)
Without further testing, all we can do is speculate. I do know my SLR-106FR barrel's throat looks like it has a lot of wear for only 6-7k rounds and that it now shoots 6-7+MOA, with the same ammo (75gr Wolf gold made by Prvi Partizan) from the same lot I bought when the rifle was new, that it used to shoot close to 2 MOA with. That same ammo does still shoot 2 MOA out of my pencil barrel 16" AR-15. I shot Russian-made Wolf and Brown Bear ammo almost exclusively out of the SLR-106FR at a firing schedule varying from 3k-500 rounds a year over the course of about 4 years, mostly at competitions and informal practice sessions where both slow and rapid fire were used (no magazine dumps- ever. Just rapid 2s, 3s, and 4s, per target for about 30-50 rounds over the course of a few minutes as in 3-gun, etc)
I have one slight bt of heartburn with this article in that it keeps referring to steel case vs. brass case in the title and a lot of the statements
The Lucky Gunner article refers to steel case and brass case because that's what the author originally set out to examine the difference between. The phenomenon with the bimetal jacketed bullets was an unexpected discovery. The case material does not play into barrel wear at all, only the jacket material.
Evidence seems to suggest, at least with .223, that the difference in wear between bimetal and copper jackets is significant and appears to become more significant the more rapid fire is used. Without more detailed knowledge of the subject however, there is still room for the Russian powders used to be at fault, or at least a factor. All that can be stated now is that current Russian-made steel cased .223 ammunition seems to cause greatly accelerated throat erosion and premature loss of accuracy compared to typical brass-cased .223 ammunition.
IIRC, there exist on the internet documents of US military testing of steel jacketed .30 caliber bullets, testing with said bullets using barrels with various different linings (chrome, etc). That information may offer some clues to help roughly extrapolate wear performance in a slower .30 caliber rifle like a 7.62x39 AKM.
Based on my experience and what the gathered information seems to indicate, I suggest users avoid using bimetal jacketed .223 ammunition in rifles that can't easily and cheaply have their barrels replaced.