What are considering as a threat, man or beast or really large beast?
I shoot the WINCHESTER White Box 110 grain .357 magnum load the most for my .357 magnum revolvers. If I were going to use it for hunting, I would use the longer barrel guns and go for a heavier bullet, but I do not hunt. That leaves me using it for self defense and the range. The WIN 110 grain load is cheap, I can buy it at WALMART for $25.00 per box of 50 and the recoil is not bad in a K-frame size gun or larger. I have shot my RUGER GP-100 with a 5 inch barrel using the original wooden grips, which is something that I almost never do as the recoil is not really heavy.
My agency issued the 110 grain load when I first joined and were issued revolvers. It worked well in the field for us, although some units in my agency used the 125 grain jhp, which is a lot hotter.
The recoil, muzzle blast, noise and flash of the 110 grain ammo is like a hot 9m.m. +P or +P+ load with about the same performance.
The 125 grain load has a top of the line reputation as a man stopper, but it comes at the price of harsher recoil, muzzle blast, more noise and a really bright flash. You however can get it at WALMART in 100 round boxes from REMINGTON, both in JHP and JSP. I have seen both types.
The 110 grain ammo is loaded much milder to a velocity of @1,300 feet per second, while the higher pressure 125 grain load exits a 4 inch barrel at @ 1450 fps.
The heavier ammo will not be more effective for self defense and is likely to be both less effective and over penetrate. If your goal is self defense, I would go with the 110 grain jhp or the 125 grain depending on how well you shoot the ammo/gun combination.
If you intend to hunt, then a 158 grain round from a 6 inch barrel would be a better bet, but from a 4 inch barrel, they are moving too slow to reliably expand in most brands and will kick harder than the 110 grain ammo. These would also work again smaller threat animals like a black bear (in Florida, they are not that large). Against pack animals, like wolves or feral dogs,you might do better with a 9m.m. with a large capacity magazine.
If your worried about a brown bear, I would forget the pistol and get a short barreled shotgun and load it with slugs!
Jim