A number of years ago, I began reloading .32 S&W Long for a new Walther GSP-C, starting with 500 pieces of new Lapua brass and a new Redding sizing die. I like to resize even new cases before I load them, and started noticing scratches on the cases after I'd run a few dozen through the die.
It turned out that what I was getting was galling of the brass in a few spots on the inside of the carbide ring, and that was giving me the scratches. After some discussion with a Redding tech, he explained that brand new brass is much cleaner than any that's been fired and tumbled (not sure if that's also the case for the newer stainless-steel pin method) and that's what can result in the galling. He recommended I clean the galled brass out of the die and use light lube for the first sizing of the remaining brass, both of which I did, and had no further issues. He also said that subsequent sizing of the same brass sans lube following firing and tumbling shouldn't result in the same problem, and that turned out to be the case as well.