A clerk at Gander Mountain explained to me (and PLEASE, don't rely on this as gospel) that black powder guns are not considered firearms in the U.S., and not covered by any firearms legislation. I take this to mean muzzle-loaders are not covered by Federal law, which is what you need to worry about. When i asked at CBSA at the Prescott crossing, i was told that the gun is left there until registered, and when you get the certificate, you go pick it up. My suggestion would be to wait for the death of the LGR, then if what I was told is true, you should be able to go buy one, show CBSA your PAL, pay whatever taxes they want, and you should be good to go. That's what I'm planning, anyways.