The mold:
The giant pellets:
In action:
I based the design on a JSB Exact Jumbo .177 cal pellet scaled up to 3″ diameter with slight modifications. I had a local machine shop make the mold to my specs, spent a couple hours with a file tweaking alignments and on the lathe polishing the core pin for easy release, then set about our first casting session. Here are some photos. Projectile weight about 7.3 lbs, cast out of 1:40 tin:lead.
Check out the full thread and more pictures – HERE
Hat tip: Anders R.
By gluing on magnum rifle primers!