Your Hdy Whitetail ammo with the 140 gr Interlock (cup and core bullet) will work just fine on black bear. I actually prefer the 140 gr bullet weight in the 270 for its balance of velocity and weight for expansion and penetration, but this is just my preference.
If it shoots well in your rifle, go forth with confidence!
The average black bear taken in most areas is not overly big or tough. The 400 lb plus bear is the exception, not the norm. So the 270 Win will work just fine. Your ammo is still packing more than 2000 ft. lbs of energy at 200 yards, where the majority of bears taken are within this distance. Plenty, even for that monster bruin, should you encounter one!
As always, bullet placement is key. The double lung shot is very effective, and as stated above they won't get far.
If possible, aiming to break the offside shoulder with this shot helps do more damage and imparts more shock on the bear, but will most likely limit full penetration for a better blood trail for tracking.
The Fusion is also a great bonded bullet. I haven't seen a rifle yet that would shoot these at least acceptably well. If it shoots well in your rifle, I wouldn't hesitate to use it on a black bear.
I also like the 140 gr AccuBond bullets. While not having used it in the 270 Win on black bear, I have used it in other calibers on black bear with great success. They shoot well in most rifles from factory ammo (Nosler and Federal), and if you handload, are one of the most consistently easy bullets to find a good load load for with minimal effort, providing good to great accuracy, and great on-game performance, regardless of caliber and bullet weight. My all-around favourite hunting bullet for these reasons, for over 20 years now.
The new Terminal Ascent bullets are another great bonded bullet that I am impressed with so far.
My 270 Win likes the factory ammo, shooting groups just over 5/8" at 100 yards.
I haven't taken game with it yet, but have taken 5 animals with the 6.5 Creedmoor with the 130 gr TA ammo to date; all one shot kills on red stag, fallow deer, arapawa rams and caribou, from 40 to 296 yards. All complete penetration with no animals falling further than 5 yards from where they shot.
I would hesitate to use this for black bear with my 270 Win.
Best of luck on your hunt!