Loaded to the German standards the 8MM Mauser is quite a step up from the .303, and plenty powerful enough for the great bears.
While I won’t argue that the 8x57mm Mauser as loaded by KNOCH & certain other European firms isn’t a LARGE step up from the .303 British service round, I’m still UNCOMFORTABLE with anything less than my 9.3x62MM loaded with the 286 grain JHP @2400FPS for any critter that is liable to stomp/maul/eat my old & increasingly fragile bod.
Btw, a dear friend of mine, who is a Pastor/Home Missionary from our church to Alaska, had to shoot a hungry female Polar Bear INSIDE The Christian Life Center, with his trusty Husqvarna BA in 9.3x62 Mauser.
(Ms. Bear had “crashed” a baby shower & scared the church-ladies out of their minds.)
Yours, TMN78247