Black bears are by and large pretty easy to kill, I personally feel like they usually have less will to live than your average whitetail buck.
My wife has killed two now with simple Sierra Gamekings in her 270 which is somewhat comparable to your 6.5. Put a bullet in the vital organs and they will die like any other animal.
Also your odds of needing to "defend" yourself from a black bear are very slim unless you make it a habit of sleeping in the garbage dump or using bacon grease as sunscreen.
