I have some of the gummy bear Hornadys in 325. I wondered what they would do in my smaller 458 American. But the 350 X bullets would be more universal on most American game. I would like to kill a few pigs with the American, then chamber to the Win Mag and do the same. Get a feel for both calibers. Packy
You can still re-chamber to .458 and use the American loads as well but they will shoot to a different point. If you do one and then the other as you suggest, they are still not interchangeable to point of aim.
