The PGC recently made some changes to the regulations that may permit certain repeaters to be used. Here are the applicable changes:
Definition of muzzle loader: Muzzleloading firearm—
(i) A firearm designed and manufactured to be loaded with loose ammunition components (projectile and propellant charge) from the muzzle or forward, open end of the firearm’s barrel.
(ii) The term includes breech-loading rifles and handguns that fire loose ammunition components comparable to a muzzleloading firearm.
(iii) The term does not authorize a firearm that accepts cartridge ammunition.
Permissible muzzle loader for the early season: Muzzleloading deer season.
(1) Permitted devices. It is lawful to hunt deer during the muzzleloading deer season with a muzzleloading firearm. The firearm must be a .44 caliber or larger single-barrel long gun or a .50 caliber or larger single-barrel handgun that propels single-projectile ammunition.
Then they'll have to change the season to "primitive firearms" IMO. I don't care what they call it, if it doesn't load from the muzzle, then its not a muzzle loader. That would be like saying a Fiat is a Volkswagen just because its roof is round.
Given that the maximum safe load listed in the manual is just 30 grains, I wouldn't plan on using that one past typical archery ranges. But with any rule changes, someone will start creating their one modern designs. Won't be long until you see the ads for the 200 yard 50 cal ultra magnum black powder repeater.