If you have a polymer frame handgun. Take a Dremel tool to the high points and add plumbers putty to the low spots. Grind, add, grind add. In a couple of hrs you will have a grip that fits you perfectly.
When casting lead put a piece of aluminum foil between the mold halves to mostly split the slug.
It will break in half on impact and the 2 halves tumble.
Ouch.