the general rule with cast bullets is go big bore or go home. 30cal in cast is about like 22cal in jacketed as far as what you will get for wound channel.
I'm assuming you want to save some $$ with the cast pills; that's fine and that's a primary reason why I'm into cast pills also. At $50 per box of 50, the 300tsx pills I run through my 375 will eat your wallet a new one in short order. I also own a mould for my 405 as it may be obsolete again one day and I want to be able to shoot it no matter what component availability is.
As far as equipment, you will also need a lube sizer, gas checks, and a lyman 30cal m die in addition to a mould, sizer die, top punch, lead furnace, dipper, ingot mould, flux, bullet lube, etc.. You may actually be spending more for cast bullets than jacketed if you only do a few hundred a year. I shoot 44mag. pistol and already have the casting equipment, otherwise I'd simply buy up more rifle bullets and forget the trouble of getting a load together. It is a lot more tedious to get a cast bullet load together than a jacketed load, and you could find out your bore simply doesn't like cast.
If this sounds like I'm raining on your parade, I'm not.... But make darn sure you know what you are getting into before you spring the $$ to do this. I personally don't shoot cast through anything under 35cal., and I haven't bothered yet to go under 37cal. cast for rifles even though I have a 338win and a 35whelen.