roosiebull I think yes and no.
First, if an elk runs 100 yards in a semi open area that is no big deal. You probably won't think of it as much different than a DRT elk. A grizzly that runs 100 yards is going to get your blood pumping because you either have a gun fight on your hands or you are frantically trying to finish it off wondering if you'll have a rodeo in the alders. Same reason why lots of people hunt elk with bows but doing the same thing to a grizzly is considered rolling the dice a bit.
I get that, and have a good grasp on that type of situation, I have been in a position with a large black bear that a poor shot was made on, and it was in brush you couldn’t see 5 yds in… he growled, I heard brush crashing, and then saw brush moving coming at me but couldn’t see anything but flashes of black as he approached, I didn’t look through the scope, just pointed the muzzle and shot, at spitting distance and luckily that turned him, and I finally saw him on the other side of the brush choked ditch and ended that situation… that scenario had nothing to do with cartridge size, and everything to do with the initial shot
I’m very picky with my initial shot on a bear for that reason, and black or brown bear doesn’t matter, if you have a bear wounded in the brush, it’s a bad situation, and a mistake was made on the initial shot, and a 30 cal accubond doesn’t bail you out of a bad shot… a 6.5 match bullet probably wouldn’t either, but it would be a better scenario.
More than any other critter, I want a soft bullet for bear (that wouldn’t change with bear species) that violently disrupts
After the scenario above, I’m even more picky with shot placement on bear, I know the only way to avoid drama is a shot angle that’s easy to tell where to shoot. I wouldn’t take a frontal chest shot most likely, I want a stationary broadside or slightly quartered shot, and I don’t care if I have to let one walk, I like hunting bear a lot more than killing bear, I’m never desperate to get a shot.
If I kill a bear this year, it will be a 77gr tmk, and would have no issue shooting a brown bear with the same bullet, it makes a lot bigger wound than an arrow, and if I ever get the chance to hunt them, it would be with my bow, with a large cut head like a German kinetic XL, because I know penetration wouldn’t be an issue