IMHO worth it, and shoot the correct brass in the correct cylinder. FA mdl 83's are built to very tight tollerances, and it doesn't take much leading or fouling to make extracting 454 brass from the cylinder tough.
As far as accuracy, due to the previously mentioned dimensions I would be surprised if you had trouble get top notch accuracy out of a 454 using 45 colt brass.
That said, it is well worth working up loads to see what is most accurate in your gun. A good revolver is capable of moa accuracy, but only with worked up loads. I've seen 1/2 gr more or 1/2 gr less powder than the accuracy load for a good revolver double the size of the group.
