When I loaded for the 30 Herrett, I used an RCBS trim die.
Place the shell holder in the ram on the press like you normally would. Then raise the ram to the top and screw in the trim die till it touches the shell holder, tighten the lock ring and you're all set to trim.
I used a hacksaw to cut off the excess brass sticking out the top of the trim die then chamfer inside and out to remove burrs and you're ready to fire form.
Sorry, I can't help with specific loads. Haven't loaded for the Herrett for several years.
Good luck and good shooting
Gary