12 Ga. Slug gun, at close range, punch a big hole, hard to beat.
This X2^ If you use a crossbow, don’t be overconfident in it’s 310 fps or whatever. I’ve tracked a bear that was hit by a xbow in the swamp, in the dark, on hands and knees with flashlights, lanterns and sidearms, etc. It is not fun, especially when the blood trail goes away, (but it is kind of an adrenaline rush). I guess the story is that bears have lots of fat layers and can “seal up” a wound. You want to put them down, NOW. I know it’s not for everybody, but I dropped mine with a 250-gr from a .50 cal muzzleloader. The only downside is not being able to see anything for a couple seconds after the shot while the smoke clears! Knowing you only have one shot at this also causes you to focus intently on the vitals and make a good kill shot. No followups.
I also second the idea of placing your bait and then scurrying up into your stand. Even better if you can go in with a buddy, perhaps on a wheeler, you get in stand and he places bait and then drives off. Bears will come in after all that commotion as well.
Good luck – it’s a great experience.