I'm asking this question on behalf of a friend who wishes to cast bullets for his .416 Rigby, for range work, as this usual supply source has stopped making them. They need to be at least 400 grains or heavier to compete in the big game shooting discipline.
Any suggestions are welcome, but in particular where he might obtain a mould to suit, (particularly in Australia).
I thought maybe a .429 mould and then size down.
Thanks in advance.