You will need to have a steel mould to make them this way. I tried the tw pot method but it was highly unsatisfactory as the amount of each alloy even with accurate small dipper was difficult as weighing the resulting bullet showed a significant weight varience which is really detramental to accuracy. This method gave by far the most consistent results by both weight and accuracy at velocity
First off cast a bunch of 50/50 (ww/Pb) Use some for general fun low velocity plinking and cut some so you have (in this case) a 60 grn nose from the 160 gn bullet