Got a set of RCBS 38 ACP/Super dies from a friend. Probably from the 70's #1 and 77 on the sizer. They appear to be all steel. No sign of a carbide ring. Nothing on the box to indicate TC. I disassembled and cleaned them, no real rust, but the lock nuts were really locked and needed Kroil to coax them loose (plus channel lock pliers). Everything looks good but the sizer has a thin ring that looks like it would be at the case mouth. I tried oil and some 0000 steel wool but it is still there. Not sure if it is part of the die or a wear/rust ring. It has a slight feel when a cleaning patch is pushed past it. Is this a normal part of the die or just neglect? I have not tried to size and cases yet but maybe later today.
As always, thank you.