For that purpose I would go with a 36 caliber and a 147 gr conical from Dixie. The mold and the bullet are actually for a revolver but the 1 in 48 twist shoots them well for me and a 3/8 inch wood plug cutter cut felt wad for it. Since I do not know of and conical or sabot available for the smaller calibers and a 32 PRB is very short ranged the conical from Dixie gun works makes the 36 in a medium twist[1 in 48 ] worth considering. I could not find a fast twist.