I don't load for the .380,(yet) but I would think you would back the load down 2 or 3 tenths. Everything else I load both cast and jacketed for, I get the same performance with just a little less powder. Whatever a manual has for a starting load for a jacketed bullet in that weight, start at the bottom of the load. Because the .380 is such a small case, just a slight increase in powder, will raise the pressure much more quickly than a larger case like a .357 or .44. gypsyman