You know 100+ years ago when gentlemen went to the field in search of really dangerous creatures, it wasnt uncommon for them to have a LARGE Bore handgun. It usually had two barrels and was typically based on a Double Rifle or perhaps SxS (or O/U) Shotgun action. Calibers and cartridges varied; but never under 40 caliber and as large as 577, although actual shotgun rounds (slugs?) werent unheard of...
Today we call them HOWDAH pistols, named after the "saddle" where the hunter rode on the elephant when in search of the worlds largest cat. Perhaps not as heavy as a Brown bear but certainly as dangerous and deadly when attacking, and more to the point FASTER.
The HOWDAH pistols, started as muzzleloaders and progressed to cartridge guns. They were at their height in the exposed hammer days; but continued into the hammerless period. Paper target accuracy wasnt so much a concern, as was ULTIMATE power at a range somewhere between bad breath and contact distances. The most common cartridge versions were in .577 Snider. Sadly there arent any modern cartridge equivalents. At least not in the power range we require for this role. Perhaps it one were to be available in a suitable cartridge, think 45-70 or one of the 50 calibers.
I bring this up because after 12+ pages of "this is my favorite" and "these are popular" and "you need to practice"; I havent heard one suggestion to BRACE and wait for the charge, then SHOOT when you cant miss. Of course 454 and 460 and 500s have serious recoil and are hard to make 5 out 5 hits off hand at 25 yards. Thats not what is required for a charging Bruin; a couple of snap shots at arms length will do. Even a "puny" 44 magnum will stop a charge with a head shot at arms length (ask me how I know).
As for me, I have serious lust for a modern HOWDAH pistol and a modern Howdah power cartridge. Im exploring the possibility of something in 45-70; but Id prefer 50 caliber or larger. I have a couple of ideas that Im working out.