I am not sure which organization our rules are borrowed from.  As written, currently c&b is allowed for our muzzle loader pistol event - 1 chamber loaded, all capped.    I have some personal confusion as to the last part - in every other bp event, capping is done on the line (I don't know if they are requiring the 5 surplus caps to be snapped). 
Irregardless - issues arrose on the c&b line that put into question the future of that event.  If discontinued, I would not be surprised if the muzzle loader pistol event rules were also modified.  I do not know what the issues were, but do understand that shooting rapid/timed fire c&b as a line rather than a staged event puts a large strain on the safety officers.
Thank you for your twist replies.  1:20 is considered too fast a twist for patched ball in rifles, but I guess it poses less issues with pistol velocities.