I have some 125 grain cast bullets I want to try in my 357 Magnum using HS-6 powder. I have a load for 125 grain XTPs already. Looking at the load data the pressure is higher with jacketed bullets. The data show that with a charge weight about a grain less than the cast loads of similar weight. Does that sound right? Data is from Hodgdens site for XTP and from the Lyman Cast Bullet Manual for 120 grain round nose and conical nose. Those overlap but are different at the top and bottom end. I’m currently planning to go with 10 up to 11 grains in 0.2 grain increments. I’m testing the same bullet with 38 Special first to see how that goes.