Its common for hunters to compare cartridges on a ballistics table then underrate the 9.3X62; for some time I was guilty of this myself. Interestingly, after being witness to hundreds of kills during his 10 years as a professional hunter in Kenya, Finn Aagaard, and his contemporaries, expressed the opinion that the reaction of game hit with the 9.3X62, was indiscernible from game hit with a .375 H&H. How can this be?? The H&H shoots heavier bullets, faster, producing more energy!! The trouble is that using kinetic energy as a measure of killing power is a red herring, what's important is how that energy is imparted to the target.
During its heyday, the secret of the 9.3's success was in the design and construction of it's 286 gr hemispherical nosed, parallel sided, soft point bullet, combined with a modest velocity. By contrast, the .375 typically used tapered bullets, that had thicker jackets and harder cores to withstand higher impact velocities. Target density is an important consideration when choosing a bullet, whether for prairie dogs or elephants. A bear, even a big bear, isn't heavily constructed like some African or Asiatic game, so choosing a bullet designed to fully expand and still produce 30" of penetration in three quarters of a ton of African buffalo, with its inch thick skin, overlapping ribs, dense muscle, and massive bones, quite likely won't produce optimum performance if used on an 800 pound grizzly. Of course shooting him through both shoulders, the spine, or a frontal chest shot with a hard bullet won't do him any good, but it will do it no better than the softer, slower 9.3.