I know there was a discussion a while back and I never saw an official cut and dried answer. I asked the question on another muzzleloading forum and a member from Washington said if it was from a dealer, had to go through an FFL.
Is a seller that has an FFL considered a dealer? I don't know.
The question is, can we still buy muzzleloading rifles and revolvers online from like Gunbroker?
Sagebrush Willy