Reloading Odd ball ammo
Check Midway reloading supplies on the web. They have lots of old, odd dies etc. Cast bullets will work just fine and you could even get a custom mold made in the correct size. Check your local gun shows for used dies. I was lucky and found some used dies in 7.62 Sharp and Hart Mag. They weren't cheap.
My friend casts very hard bullets and quenches them for more hardness and lube/sizes them with the orange bullet lube before loading and shooting in his 300 Win Mag. We were shooting gallon milk jugs filled with water at LONG distances with great success. No leading in his barrel.
I've got more than 30 die sets and most were used from garage sales, friends and gun shows. Just be sure to look inside for scratches and rust.