I convert 30-30 brass to 7-30 Waters.
If you don't want to lose cases to neck cracks, anneal before running 30-30 case into the 7-30 Waters size die to form.
When you fire form, that when the cracks appear on un annealed cases.
I haunt the funshows and buy up partial boxes of 7mm jacketed bullets.
Used everything from 110 grs to 175 gr bullets (all jacketed)
I got good accuracy with Hornady 139 gr Spirt Point bullets with case forming loads.
For fire forming loads I use up partial cans of powder and load the "start" load for a fire forming load.
For what you will spend for a casting furnace, mold, sizing die, lube, you will be money ahead just buying some 7mm jacketed bullets.
Also your lack of casting experience also points to you buying jacketed bullets.
I'm shooting these loads in a 10 inch Contender barrel, and just added a rifle barrel in 7-30 Waters.