Unless the rate of twist is quite a bit slower than 1:48", you should be able to find a bullet that will shoot out of that barrel over a wool wad
Idaholewis over at Modern Muzzleloader has had tremendous success getting stock, T/C, 1:48" twist, Hawken & Renegade rifles to shoot properly sized for the bore, grease groove bullets, over moderate charges of Swiss black powder, and an oversized for bore wool wad (.50 cal wad for .45 cal bore).
On a whim one day, he decided NOT TO LUBE that huge forward grease groove on the T/C MAXI-BALL bullet, theorizing that the excess lube was not being shed as the maxi-ball left the barrel. Just like the SkyChief Load, not lubing that big groove, and only lubing the small rear groove is COMPLETELY COUNTER-INTUITIVE.
But, wonder of wonders, all of a sudden every one of his many T/C rifles started shooting incredibly tight groups, where before they were horrible.
Who knew?? Sometimes it takes a person to think outside the box to solve a long standing problem.