No it is not required. Sabot rounds are allowed.

Truth be told the WMU I hunt is shotgun only...but allows for inline muzzleloaders to be used during the firearms season. After 2 years with a mossberg 500 shotgun ive decided against throwing lead at a deer and am now moving towards a muzzleloader for accuracy purposes.

There is also an early doe muzzleloaderseason that overlaps our archery season as well as lobbying for an early buck season for muzzleloader.