Both "Krupp Laufstahl" and "Roechling Elektro" were standard barrel steels, used interchangeably in production. "Boehler Antinit" was an expensive, highly alloyed stainless barrel steel, used only on special order at a premium price. Antinit barrels are easily spotted today: they more often than not appear nearly white. Stainless steel is hard to rust blue of course, and the resulting "black" quickly wears off.