I have seen a Browning Superposed 20 Ga. and a Winchester 12 Ga. 101 that both had barrels that were "splined" or scratched by Steel Loads. This was how ever back around 1980-1982, the Steel componets are supposed to be better these days.

My Richland Arms 10 Ga. choked full & fuller shows no signs of damage with steel. It is sort of a clunker, so I don't worry too much about it.

Mine's a tale that can't be told, my freedom I hold dear.