I really love the idea of a 9.3 x 62, but I have and use 3 - .35 Whelens - an ordinary Rem 700 classic, a Sako AV classic re-barreled to .35 W with 24", 1-12" twist, and a Ruger #1A re-barreled with a 24" 1-12".
I have shot right through nearly all the elk and moose I have used these rifles on, (more than a dozen) with 250 gr. Speer Grand slam bullets mostly, but also Hornady RN, Speer Hot Cor, Remington factory loads, and even a few 225 grain bullets. I just can't believe there is any advantage to any cartridge ( or bullet weight) with more penetrating ability for critters that size, including brown bears.
Buy a .358 Norma if you like, or a 9.3x62, 4, 6 whatever, but you won't kill bears any deader than you will with a Whelen. It's fun to dream about new rifles though Isn't it?
