Apart from the question mark, I don’t even understand how this is a question...
Same here.
As many have said, either choice would work.
I wouldnt think twice about shooting a black bear with a .223 and a good mono...
Ditto, with one caveat... depending on where you hunt, you may factor in the difference between killing a bear and finding it once dead. Have seen them killed with .22 rimfire and a couple of .22 centerfires in the hands of confident capable hunters, all east of the coast range.
My grandson killed a called black bear last evening, 25 hours ago. He has been seeking an elk load for his Tikka 30-06, and he hunted bear with it because a 180 grain Swift A-frame is the most accurate bullet he's tried in his rifle. 58 yard shot, almost broadside, bullet hit center of ribs angling back a smidge to exit at last rib. The bear went 30 yards and was dead within seconds... and was exceptionally difficult to find. Innards plugged the exit, zero blood trail found by some good trackers with him. The bear was finally found by careful search for occasional broken ferns or squirts of scat, plus some grid work, and the searchers walked past it twice inside of 6 feet without seeing it.
OK, first bear, standing in the only open spot where he could see it, he likely should have broken its shoulder given the thick brush. Any hit that did not drop it on the spot, with any rifle bullet combo, would mean trailing the animal at least a few steps. I had one go 15 feet in super thick brush, surprisingly hard to find and a nervous search for it.
This musing is likely more about bullet placement than caliber, but a larger exit hole to leak is usually a good thing.
None of this applies where you can almost always see your boots, see ground across a ravine or canyon, go around or under vegetation without having to part it, etc. You should have seen how scratched up those men were last night by the time they found the bear and got it to a road.
Having nattered all this, I'd take the one I shoot best and most confidently, and if equal, it would be the .06.
A ton of overkill beats an ounce of underkill.
