Black bears even in the 300-400 pound class are easily killed. For my .338 I standardized on a 225 Nosler partition @ around 2850 fps, imr4831 powder, cci250 primer and WW brass. You will get total penetration @ any angle you will shoot from in your particular situation.Your Hornady interlock is also a very fine choice.
A 250 grain bullet is totally unnecessary for this size- class black bears. Neither is a .338 required, but it will certainly do the job.
I do not like shooting heavy recoilers from a treestand.
A light handy 30-06, .308Win. with decent 180 grain bullets flattens any of those bears.
Having observed lots of customer mistakes in bearcamp,may I recommend the following ?
If you are an old hand at this, then please ignore my un-asked for advice.
1.- Have a scope with heavy cross hairs to find black bears in a dark forest just at dark.
2.- have a scope with 2 or 3x powersetting as an option.
You need clarity and field of view not enlargement.
3.- Unless it is raining, no gortex in the stand, it is too noisy and will easily spook a bear on the bait.
4.- make sure your rifle is smack on at bait barrel distance. At dusk you may have enough trouble making head out from tail on your black bear at dusk in the trees. This is not the time and place to hold low or high,one of the main reasons of flubbed shots in this type of hunting.
5.- Visualize the lungs, spine and heart in the bear from the angle you will be shooting. Scope one of the frequent non-shooter bears like yearlings and mammas with cubs, visiting the bait. Great exercise and confidence booster.
6.- Urinate in a wide necked pop bottle while in the stand. Empty well away from the stand.A good reason to drink warm water instead of coffee just before going in the stand. Coffee/tea is a diuretic.
7.- No un-wrapping candy bars, sandwiches etc. while waiting for game in the tree stand. Bears easily hear that. Ditto un-screwing noisy thermos bottles,or pop bottles.You can unwrap some immediatly after you get into your stand for later consumption.
8.- Shoot a trophy not a puppy. Do not shoot the first bear you see unless the body is as big or bigger then the bait barrel.
Enjoy your hunt.