I picked this up off of ebay, looks very similar to a CH4d but the "ram" that shellholders snap into is marked RCBS. Did RCBS ever make one like this? It seems to work pretty well just testing it on a handful of 223 brass
I have an RCBS unit, but it looks completely different than that one. If you don't get an answer here, maybe sending a photo to RCBS's customer service people would help.