Randy,
IMHO, and with all my respect, by the time you are done sizing (several times), trimming, cutting, annealing (yes, you will need to), fire forming, and then sizing and trimming again, you will have spent a formidable amount of your time, and which by the way, only ending with a guaranteed inferior piece of brass. Please don't ask me why I know.
May I strongly suggest you sell your once fired 308 brass, and apply those funds to obtain some new Norma 6XC, or at least Win. 22-250 brass?
I guarantee you will be a happier camper, with newly freed shooting time in your hands, unless of course you are perhaps retired, unemployed, un-married, have no dog, believe in self sacrifice and mutilation, etc., which in case, I would perhaps only then agree pursuing in such a voyage.
Hope this helps change your mind.
Andy