You will need a set of dies, also you will need to lube the cases
because of the bottleneck. I use imperial sizing wax, and a little
goes a long way. You can get it at Midway or other online vendors.
I have also used Hornady One shot...but I am cheap, so the Imperial
gets the nod.
Data for lead is a bit scarce. Most data shows jhp bullets, which
are much stronger than lead or plated bullets. You will probably
need to keep velocity under 1200, unless your bullets are sized
properly.
Which mold are you casting? I have shot the Lee 120
truncated cone out of my 38 super and 9mm. It is accurate in
both guns. I can shoot them as cast...they are falling at .3565
to .357. As cast diameter, as I am sure you know, will vary based
on your alloy, etc.