Strawhat, when Uberti started making conversion revolvers, they did increase the size slightly so they could chamber .44 Spcl and .45 Schofield rims. This was also done so bores would not line up between cartridge and percussion guns, to prevent putting the softer steel percussion barrels on conversions.
But they did not increase the size of their C&B guns.
As for the little .380, I do not know.