You are most likely going to kill the bear with core lokts or the fusion, but there is much better ammunition out there if you are concerned with the .243. That ammo will fragment pretty quick, so maybe a nosler partition, or bonded. Yeah, it might be 3x the cost for the ammo but it’s higher quality for sure.
The nosler partition is a great projectile. Nosler also makes a copper bullet (etip) that has good reviews. Copper bullets shed very little weight hence the performance/penetration is more like a heavier lead core bullet.
I've only shot 4 black bears but they don't seem any harder to kill than deer. Shot all 4 with my 280 using Nosler Partitions. 3 died where they stood , 1 ran about 100 yards , hit him a little high. All lung/ heart shots.
I would use these and you would probably be good with even a shoulder shot. CoreLokt's would probably also be fine, but I think I might go for a little more insurance, with a stronger deeper penetrating bullet than a CoreLokt in such a light weight. The copper bullets as recommended by JDK would be my second choice. I just like the Nosler's combination of penetration and expansion.
Oh, I'm sure it'll work if she hits the lungs. Its if she hits the shoulder instead that I'm concerned about. I know that my .308 will just breeze through, but a .243 might have problems. She's more than good enough at the range, but you know what that's like against actual field experience.
Trigger time trumps a lot of things, including information found on the internet. Get her shooting, a lot, and then have her stick a 100 gr. Partition through the boilerroom of a bear. After that call the taxidermist to pay for the rug.
Black bear aren't all that hard to terminate but are different than a deer. Killing stuff isn't hard, we make it so.
Trigger time is NOT a problem here. I can't go to the range anymore without bringing her. I just pack the .243 out of habit nowadays. She's been going to the range weekly, even twice a week sometimes. When there, she'll typically shoot 20-30 rounds. It's getting expensive, so if Partitions it is, she'll be practicing with something cheaper.
I've seen marked improvement in her skills. I am confident she could hit the boiler room at 100 yards, and we aren't going to be that far away.
No doubt she is going to be a good enough shot. Are you going to be in a stand with a rest or walking thru the woods? In any event it would be nice to do some off hand shooting and maybe standing leaning up against a tree, like in a hunting situation.
The mental aspect and excitement of the hunt will be the thing to overcome. It would be nice if you could get out and show her some bears before the season, so the shock of seeing one is not so great.
You probably have these things covered, just things that I would think about getting a new hunter ready. I have some experience with my three kids.
I've said this before and got po po'd. IF my rifle shoot partitions well, especially in the Federal Premium line of ammo, oftentimes it shoots the cheap Federal Blue Box ammo to nearly the same point of impact. It is a cheap alternative and when the time comes to shoot the pricier ammo, adjustments are minor.
I have also had several rifles that patterned Partitions like a shotgun.
Of what I currently own a Sako AII in 308 will not group 165 or 180s. Never tried 150s. Shoots those bullets minute of earth at best
in the past, 700 ADL in 243 and 270 and a 7600 in 30-06. The two 700s were outstanding and shot everything else well. The 7600 was eh so it may not have been the bullet
i also owned an Interarms Mark X that was accurate and shot Partitions OK at best. I did kill a moose with that combo