The majority of bears I have harvested where via the bow and no back up weapon. That said I have harvested a black bear with ML, 300gr xtp under 120 gr RS, shot was 30 yards bear travelled maybe 30 more and gave it up. Bullet slammed the opposite shoulder and exited. My partner also shot one the same evening with 240xtp and100gr pyrodex pellets, his shot wasn't even 20 yards and bear dropped, rolled, bit and scampered 20 yards before come face to face with a pine tree to where he gave up the ghost. His bulletpunched the lungsbefore exiting the opposite rib cage. Both we're spring/forest bears which we don't take the meat from(legal to leave in the field) and we just caped them whole, soI can't say for sure they did not frag but they certainly did the job.Bare in mindnone of these where polymer tipped bullets, so I'd expect at close range increased expansion to the tip will effect penetration. Enough tocause concern,i can't say for sure but if it were me I'd follow the advice of trying the bonded version or at very least moving up to a 300gr version, if hunting bait or expecting close encounters. Just in case is the side I error on.

Good Luck