I converted a Kimber to fire the .460 Rowland. I ended up moving the kit to Stalkingbear and the pistol to Goju, but when it was together it kicked Cane's ass in our build off.
My impression was that it was a hell of a lot of power in your hands. A ridiculous amount of power to be honest.
The kind of "boom" that has everyone on the range looking in your direction and muttering things like "Is that a .50?"
I ordered some 185gr. super hot loads out of the gate and they were awesome. The muzzle break works really well, keeps you on target and the recoil is well managed. Mind you it was an all steel gun to begin with, so it wasn't a lightweight carry piece, but with all that extra power it was like a whole new day.
It was a nice project, but the ammo price and availability just didn't really suit me to be perfectly honest. I went to re-order and the rounds I wanted were backlogged. I don't reload for my pistols (yet), so it just seemed like a pet project that had run it's course.
And Cane was still yanking his pud with the mental midgets at Colt because his Uber weapon was delayed due to complications.
For a bear situation? Unless you have a high cap, 10+1 rounders, I would be hesitant to "recommend" it. The .500 S&W is probably a more serious deterrent .
I would trust the .460 in the right hands, but I wouldn't recommend it to someone else just because round placement is going to be the key to staying alive in a bear encounter.