From Steel Challenge Rules:
4. "IDPA STOCK SERVICE REVOLVER DIVISION"
"Any revolver of 9mm/38 Special Caliber or larger with a barrel length of 5" or less (7 & 8 shot revolvers permitted, but may only load six rounds). No external modifications other than changing sights and grips will be permitted."
and
"REVOLVER DIVISION"
Entrants competing with revolvers will compete in Open Class AND overall Revolver. Open Revolver has no restrictions for maximum rounds or use of optics.
So, it appears that you can, but I don't really understand what the divisions really are. The rules seem to be very vague and not very well organized with headings and descriptions.
I was thinking the same thing. For all other divisions you have to meet the equipment for the division( production, limited, ESP, etc) but I guess for revolver you do not.