AR won't cycle steel cases

[fanofflyn]

I don't know because I don't run steel cases in my AR's, but I read somewhere that some of them had problems with the Lacquer coating the cases, and that when run hot, it starts depositing in the chamber, and when the gun cools, it becomes a problem in the chamber. Does anyone know if this is just hearsay or if this is really a problem with some brands. I now see aluminum cased ammo too, and I don't know much about it, but I would guess that wouldn't be as much a problem, but that is only a guess.