My son just bought a 300 Win Mag and wants me to load for him. He has H-1000 powder and 178 Eldx bullets. Has extended magazine so can load to 3.56 long. Since components are so hard to come by just would like to know what the best jump would be for that caliber so I don’t have to burn up a bunch of ammo. Read in a previous post the 300 WM like a big jump but mostly because mags only allow 3.34 OAL. Any thoughts?