Yes. The older models came with large & small rotors to be used interchangably for rifle or pistol.
Unscrew the knurled lock nut from micrometer all the way off. Loosen & completely remove the 3/4" hex nut from the mic. screw next. Push the mic. screw up into the hopper & carefully slide the rotor out of the body. Scotch-brite should remove any dirt or roughness unless it's too badly rusted. You want to polish, not remove metal. Clean it thoroughly with brake clean or the like (no oil residue). Gently & elegantly (no reason to force anything) reassemble in reverse to the above order dry or with a little graphite.
Smokeless powder has minuscule amounts of graphite mixed with it so that should keep everything lubed unless it sits in a damp place for months between use. I hear RCBS has great customer warranty service if all else fails.