Rowdy,
In Tennessee the wildlife agency is particular in their wording in that it is 'muzzle loader' or 'gun' season. The blackpowder loaded cartridges are considered under the gun season so no we can't use the 76, 73, etc in anything but regular gun season. Same here on muzzle loader, most all you see are the modern in line. My own muzzle loader is an old CVA Hawkins but these are few and far between these days in the field. That I know of, no one has suggested a black powder cartridge season here. It is a good idea.
P.B.