I've shot one with a 6mm Remington and 1 with a 270. I've seen em shot with everything from a 22 hornet all the way up to a 45-70. They're not overly hard to kill
My only bear was with my bow; Opening day of blacktail season. I recently inherited my grandfather's Model 81 in 35 Rem., so I intend to take that out, but between the cartridge and open sights, it'll be a short range proposition. I believe he did all his black bear hunting in PA.
I've used a recurve, compound, win 94 30-30, 308, 7mag, 280ai, 338rcm. Plan on using a 22-250ackley or 6.5 creed this year. I think the fastest death was the 280ai but they all worked just fine.
Doesn’t take anything special unless you are shooting long range. Killed a few with a bow, 223, 300 blackout, 7mm-08, 300 saum, muzzleloader. I like my 7mm-08 right now and would take that or something similar if I was going on a rifle bear hunt.