I have the 35 whelen built on a custom Mauser action with a Maclelland barrel, a Ruger no1 in 9.3X74r, and an excellent 338 federal built by ATRS with a carbon one barrel. All three will do about the same on game up to moose size, I would not hesitate to use either for grizzly or polar bear and have. If you hand load for the 338 fed,try Lever Revolution powder, in my rifle with 225 grain accubonds it matches the 338-06 velocity and will kill any game out to 400 on this continent, nothing else is required. This is not a hot rod load, it is listed on their site, my rifle comes to within 20fps+ of their spec. I like it so much, the 35 and 9.3 will eventually be sold off if my kids don't grab EM' first. LOL