Have shot 3 bears with 150gr Sierra GameKings from a .270win. all died instantly at ranges from 60 to 270 yards. they did leave a helluva mess inside though. think explosive.
shot 2 black bears with Hornady Interlock 150gr SP in the 70 to 120yrd range, both went less then 40yrds.
Through guiding I have seen another 6-8 bears shot with 270's in a varied supply of loads, all went less then 40yrds when shot behind the shoulder.
the only "bad" 270 hit I've seen on bear was a 6'8" boar shot with a single 130gr Winchester powerpoint in the liver. he crawled about 60yrds, went under a fallen tree and was recovered about an hour later. not ONE speck of blood.
I've seen 6 moose (one of my own) fall to the .270 win, all went down very quickly. Mine went down instantly to a Imperial Factory 160gr RN load that chrony'd @ 2350fps MV
bears need neither a heavy caliber or super bullet. side one through the boiler room, wait 20mins, go collect dead bear. we won't be far. they die easy.