Alpo the dog 444 sounds hilarious
it would be a labour of love with no tangible rewards.
If you want something simular neck down a 30-40 shorten the shoulder and AI it, a lot simpler. Or even better if you want an AI do it with a 7mm-08. I have one of those and it is an incredible cartridge to hand load. There are several version of these. Lane Simpson designed a very good one and I designed another one.
Oh, I forgot to mention that neither the Simpson nor mine is suitable for the Handi.