This subject has probably been chewed over before so many times as to numb the experienced shooters. Sorry! However, I just bought a 450 Marlin and I want to resume bullet casting. I did it before only for handgun targeting. Now I want to use it for hunting larger game, such as elk and moose. I suspect that about 400 grains is the optimum weight...good penetration without sacrificing speed, and causing cycling problems. Does this seem right? Also, who makes the more easily available quality molds? Custom moulds, unless they are outstandingly better would not interest me. Who offers the best gas checked mold in this category? Thanks, guys.