From a smoothbore, a properly loaded, hardened (straight WW) round ball IS my choice for grizzlies in camp as the 12 hits much harder than a .375 at close range.

I addressed the oversize ball - 4th post above this one - don't do it, please.

By all means, use a .724" ball (NOT .735") and the wads suggested to 'hold' the ball in the centre of the bore as it accellerates up the bore.

As I noted above, some shotguns bores today are oversize - some up to .735" and some even up to .740" or perhaps even larger. In a .740", you could easily use a .735" ball - yes - as long as it's undersize for bore size and lubed. Slugging the bore is the best way of finding what size your bores are. Dial calipers will give a close dimension but not as accurate as slugging the bore. If a .735" ball willnot fall through the bore, it is too big, will raise pressures and you don't want that. too high a pressure spike can seize the action, just when you need a fast reload, like chasing the bear out of camp. Shooting one is a last resort - firing in front to scare him away is the best move. Inadvertantly shooting one just because he's close, will not go over well with the game branch - something to consider.

As a side note, I just mic'd my new Mossey 835's rifled tube - .005"depth of rifling @ 35" twist and a groove diameter of a tight .722". A .7225" WW ball from my Tanner mould marked .725", goes to the bottom of the grooves, perfectly. Shooting a .735" ball will GREATLY increase pressure, making reduced loads necessary, heavily leading the forcing cone - all things I don't want. I can achieve over 1,600fps with a ball or the Lyman sabot slug. It's almost 14 bore in size. I could use the .7225' ball, as-is @ 565gr., lubed, but will achieve greater speeds (and perhaps accuracy) with the 506gr. WW Lyman slug inside a WWA12 red field shot-cup. They are .682" in diameter so little is lost in size and amazing accuracy is claimed for them - 3" from a smoothbore & 1 1/2" to 2" from a rifled tube - at 50 yards. the 506gr. WW slug will hit hard, and penetrate well while not breaking up. It seems now an either/or situation - round ball or the Lyman slug inside the wad. They are very tight in the Mossy's bore and cannot be shoved into it by hand. 'm quite excited about their 'possibilities' in both rifled and smoothbores. Time and testing will tell.