I'll never down a the .45 as a defensive caliber and I will continue to own the one I shoot but why have 3 if 2 don't get use?
One good reason to have two is that if you ever do use the gun in a defensive shooting, the cops will take it (its evidence). You will get it back, once everything is settled, but it could be weeks or even months. Having a second one means you don't have to be without, while the wheels of justice grind slowly.
Having a 3rd one is just...fun.
If I were concerned about medium to small black bears, I'd look at a 180gr hard cast bullet over a stout load of 2400 or, even better, H110 or W296
Seems like everyone today thinks they need 180gr bullets in the .357 for anything serious, other than self defense. I don't. I'm fine with the 158/160gr bullets, which have worked just fine in the .357 since 1935.
180s got popular in silhouette shooting, having enough greater momentum over the 158 to do a better job knocking down the ram target at 200 yds. No game animal can tell the difference.
In my 45 years experience loading and shooting the .357 Mag, H-110 and W296 are not "better" than 2400. None of them will give their full potential out of a 4" barrel. 2400 is my go to powder for .357 magnum loads.
Get a good 158gr, start with 14gr 2400 (magnum primers), and if that's not enough, slowly work up. You have a fine, stout gun, and should be able to take loads close to, or matching the original .357 loading (which is more than most "regular" factory ammo today), but your short barrel won't let you match the original velocity. (158gr @ ~1550fps from an 8 & 3/4" barrel)
Most .357s shoot .38 Special well, but some just don't. One thing you can try, once you get loading, is to try .38 Spl level loads in .357 brass, and see if they shoot any better than regular .38 Spl.
Do not use 2400 for .38Spl loads. You CAN, and it will work, but its a waste of good 2400.
Use a medium burn rate powder (like Unique) or a fast one (like Bullseye) for .38 Spl level loads. BE CAREFUL when using fast powders, check carefully to make sure you don't double charge a case. A double charge of Bullseye will blow up even a Ruger!! Also use standard, not magnum primers for light loads and for medium & fast burning powders.
Use 180s if they appeal to you, but don't think for a minute you
need them.
Enjoy!