I bought my one and only muzzleloader, a T/C Hawkin .54 cal kit rifle, back about 1990 as a "why not try it" venture. I chose .54 as elk and moose are the primary pursuit here, with whitetails and mulies being incidentals while out hunting. My hunting rifles at the time were (and are) 30 Newton and 358 Norma Magnum, so I was open to exploring different paths.
But I am also lazy, so I wanted to try conicals to avoid the bother of patching. And I decided a heavy conical would be best for critters the size of elk and moose so a twist rate favourable to conicals was also the ticket. The T/C Hawkin, as I remember from back then, was the only rifle in the non-Internet days I could find in catalogues that fit that bill.
As I wasn't invested in completely traditional. I ordered one of Lyman's combo moulds with a conical and ball cavity. The grouping with the conicals after I worked up a load was so satisfying at 200 yards that the plastic container of balls I cast the day I started is sitting somewhere unopened and the patching material intended for shooting has long since disappeared being used for cleaning. I did install one of their rear aperture sights from the beginning, and that obviously helped tremendously. And I HAVE shot an elk at just a shade over 200 yards by pace that I couldn't get any closer to; the results were immediate and satisfying. Boom - flop.
One thing... the recoil is quite stout. The killer curve in that brass buttplate owns much of the blame for that. I shoot with a recoil pad at the range (with all my rifles above .22 caliber, always have) which makes it not that big a deal, and when shooting at animals, I never think of or notice it. HOWEVER... 30 years later, I'm a senior citizen and not quite as beefy as I was 30 years ago when I was an infantryman in the military. I think a day will come when I will have to consider lightening up on the charges and/or putting a .50 cal barrel on instead - shooting conicals. Or maybe a replacement stock with a flat/wider butt, perhaps still fitted with a kinda traditional brass buttplate.
I did consider a drop in subcaliber .32 barrel with a fast twist for conicals for fun... but the $300+ price tag for that drop in was more pricey than what I was interested in. I have no quarrel with the asking price, and 30 years ago I would have paid it gladly. But I have a lot more hours of shooting at the range or hunting behind me than I have in front of me at my age. As it is, I have a problem keeping the dust shot off all my rifles, shotguns, and handguns. The sub caliber would probably end up collecting more dust than time being shot.
Anyways, in my very limited experience, getting conicals to deliver the goods in my T/C Hawkin .54 was easy, probably because of the favourable twist rate to begin with. I don't know whether Lyman still makes that combo mould; if not they're probably available on Fleabay or some of the other market sites.