....If you don't lightly lube the inside of your case necks, your casings will bind on the expander ball some on the way into the die, but much moreso on removing the brass from the die. You also run the risk of slightly changing shoulder angle by actually pulling the brass foreward slightly when removing the case.
Do yourself a favor and at least try lubing the inside of the necks. There are several different methods and devices out there. I use a q-tip and Imperial sizing die wax. Vaseline works well, too, as does your RCBS lube. You don't need a sloppy bunch of it. Simply lightly roll an end of the q-tip in your lube, insert in the case mouth, spin once and remove it. Run the casing into the die, and remove. Much better, huh? Take a dry q-tip and wipe out the case mouth. Done. I very, very rarely have any powder adhere to the inside of the neck except for a little Ball powder sometimes. I usually lube about 5 case necks before I re-charge the q-tip with more lube. When it gets raggy-looking, get a new q-tip. They're pretty cheap.....