My dad used a .270 with 150gr federal premium nosler partitions on black bear, big black bear! spot n stalk....200yds etc....not over bait at a 200 lb cub.....

I'd recommend any premium controlled expansion bullet, so if he likes 150's get somethign nice, nosler, trophy boned bearclaw, barnes.....

I think those BTSP's might not want to penetrate, im my mind they're softer than other bullets such as noslers etc....geat for deer etc....but not so much an elk. Sure they can work/do the job, but if you get a bad angle and its your only shot of the hunt....and it gets away because of poor bullet performance ie downhill uphill, 1/4 away....you'll have to go through more bone, muscle etc...to get at those vitals.