Hi,
My only experience with steel cased ammo was milsurp 7.62x54R from several countries, shot thru a couple of Mosins. All of it was the "lacquered" stuff, and some of it was a tad bit sticky to extract, though I didn't have any actually stick to the point of having to get out a rod and "tap" 'em out, just had to smack the bolt a little harder than usual. The sticky stuff "felt" a little hotter, too. A couple of my Mosin buddies shoot tons of steel cased ammo, the copper looking variety, and haven't reported any problems.
Now, that's all bolt action experience. Flip the coin over, to owners of autos, and the complaints roll in. Thing is, the ones I've heard were shooting "Commie bloc" ammo in "Free World" guns, which I think tend to be considerably tighter than your average AK (that I'm told may also have a chromed chamber. Slicker maybe?), and that's where the problem comes in: while the steel expands to seal the chamber, it doesn't "snap back" the way brass does, so a tight chamber will grab it even under the best of conditions. Add some "glue" in the form of that lacquer coating melting a bit, and problems are easy to understand.
That's just one tiny observation of a much bigger world, of course.
Rick C