You cannot hunt the big bears with a smoohbore, legaly, in B.C., only deer and black bears.
; The power is there, especially in a camp setting - nothing better than a right and left of heavy hard balls. They are certainly better than ANY 1-1/4 oz. Foster slug. The sabots are quite inferior to either. why take a .50 to a .73 battle?
: As to powders for the long case, I'd select one of the sloer burning types meant for shootng heavy shot loads and work from there. A good understanding of handloading is a pre-requisit to developing loads for the 'pelter'.
: One should have a chronograph as well, whether developing loads for a rifle or a smoothbore.
: I would expect the 3" should be capable of getting a .722" to .724" ball up to about 1,700fps without too much problem - be careful out there.
: The 'typical' heavy black powder 12 bore load of the 19th century was in the 1,500fps range. It was a kicker with 190gr. black powder. Loaded to that velocity today wiuth smokeless powder makes for a very powerful, yet moderately recoiling round, and capable of being shot in any 12 bore gun made. Results will probably be better in cylinder bores which of course, allow larger, heavier balls. The balls must be the same size or smaller than the choke constriction in a choked gun. Mic the bore and the muzzle of your gun. Most full chokes measure around .690" at the 'end choke', roughly 40 points (thou) of choke - standard.
: The shot-cup bases, if loaded cup-up underneath the ball, effectively holds them in the centre of the bore, no matter what the choke. This is how mine shot so well, even though they were only .684" in diameter at 480gr. weight, shot from .725" tubes. I put one wad base, cup-down on the powder, then wads if necessary then one cup-up to centre the ball. With black powder loads, I put a thin card wad on top of the powder to protect the plastic from melting and coating the bore. With smokeless, the temperature isn't as high and melting isn't as bad. It's pretty simple loading, but did take some time to develope the system and then accurate loads were the result.
: The 575gr. Brenneke (or Vitt-Dynamic) slugs would be about the best of full sized slugs as they're solid. Trouble is, they're also soft and aren't going very fast. Handloads can increase their speed, to Lyman's printed loads of 1,500fps. Using those loads, the round ball should develop the same or higher velocity.