Originally Posted by
super_hunt54
Its because that action can be rebarreled for smokeless cartridge use. Same with several other smokeless capable rigs. That's probably the basis for the writeup I saw and just didn't remember that particular passage.
Yes, so now you are understanding that it is the action and not the barrel. This is nothing new. All actions that can be converted into a center fire gun has to have an ffl. A barrel being rated to handle smokeless pressures has nothing to do with it. So one could build a muzzleloader that can handle smokeless powder and not require an ffl.