Loner- Maryland's law is about the same as Mississippi. Muzzleloaders can be bought without background checks, no questions asked. Encores fall into the rifle category since you can switch out the barrels, so they do require paperwork to be filled out.

Back to the Wal-Mart question, I might be stopping by my local Wal-Mart this afternoon so I'll have to see if I can find anything out.