I carry when we hike in the parks.
Will a 10mm or 45ACP stop a black bear?

Of course it will.  I'm not sure how many rounds it will take so just keep shooting until it stops!

 

Sorry, I was just kidding.  When I hike in the Smoky's I generally take my rat terrier with me so the bear will have something to eat, I mean distract him, while I'm running away.

 

I don't know anything about those eastern blackbears, but out here in the  PNW you've got better chance of being struck by lightning while holding a winning lottery ticket as your supermodel GF watches than you do of being attacked and mauled by a blackbear.

The only thing the bears care about is your food and their baby bears.  I even came across one in a Pennsylvania park that had been injured.  I walked to within about 20 yards of him, (I didn't see him until then) and saw that his side had been cut up in a fight.  He just lumbered around and payed no attention to me.  I walked away.  The end.  If you see the little ones, get out of there calmly.

Yeah black bears really aren't aggressive towards people unless you have a side of bacon zip tied to your leg. I'd honestly worry more about a tree falling on me or falling down and breaking my leg.

I found this a while back when this subject came up.  Now I know it's Wikipedia, but it's interesting that the black versus brown bear attacks seem to be running neck to neck.  A smattering of polar bear attacks are listed as well.

Any predator can decide you are food on any given day.  Odds are generally low, but quickly increase to a personal 100% when Yogi is chewing on your leg.  Having hunted bear and found that when they don't want it be found it's hard to find them, I have almost literally tripped over then when not looking for them.  

A firearm is like auto insurance.  Hopefully you never need it, but when your two day old Corvette gets totaled kind of nice to have.

Discussion of what type/caliber is best is a nice little bit of diversion, so in that vain, I'd recommend the largest caliber magnum revolver you can shoot accurately.  Then always make sure you have a friend along so you can shoot him in the leg to distract the bear as you run away.

Black Bears can and do kill people!

There have been 2 such killings within an hour of where I live, so yes, I carry when out and about on the farm. Usually it's a Model 60 S&W, 3" 357, with 160 gr. hard cast SWC's over a stiff dose of powder. Penetrations was what I was looking for! The little guy is ported and handles these loads better then you might at first expect! I don't fire such hot loads every day through it, just use up my carry rounds every 30 days or so.

Black Bear attacks.

You have the right to Bear Arms.....lol

I better stay out of the PNW then so I don't have to cause my Supermodel GF to develop PTSD and have to be treated by a psychologist and then end up running away with him and take all my lottery winnings.  

I carried my 10mm while working up in the PNW and did in fact see a black bear.  It looked at me for a few seconds then walked away from me with little concern. I waited awhile and continued my hike in a different direction.
The only time I have ever been remotely threatened by a bear was while fishing on a lake in Northern CA in the Spring time.  Mother nature called while in the canoe.  We made a beeline for the shore and I jumped off and started running towards a tree.  Well momma and her cubs happened to be near by and she didn't like the running towards her so she charged towards me.  I turned and ran back to the boat and away we went.  I ended up hanging my butt over the edge of the canoe (not easy to do and not tip over) as I wasn't taking any chances again.  

Thunder Bay Black Bear Attack