IMHO it's .40S&W/10mm.
Very few boolit molds available. You basically have TC, SWC and WFN. There's not even a lot of SWC molds available. I know Accurate has some listed in their catalog but I can't stretch my $$ that far.
I love shooting my 10mm pistols but casting for them is work, there's just nothing exciting about it like there is for other calibers.