Just go with the .380 it'll shave off whats needed for a tighter fit. May have to use a little more force. I had a bunch of .457 balls left over from the ROA (that I sold like a doughnut head) and I regularly shove them in the '58 sheriff. Shaves a nice ring of lead but they go in tight and seal up good. My philosophy Buy .380's for 36's .454's for 44's. That way you only have to worry about one size of ball for each caliber. And if a loading stand is used no sweat.
Just my .02