That is a weird-azzed list... "under considerstion; .300 PRC & .458 Win Mag, which should I go with?"
Having said that... you could consider the .338 WM from your list... shooting a 230 ELD-X @ 2900+ fps... you can reach way out there with considerable "smack."
My 338 RUM shot 225 Accubonds at. 3225 fps with a lot of H1000 powder ! Put that wimpy 338 WM to SHAME !
