According to the folks in Annapolis... a muzzleloading gun, original or a copy of an original, is legally an antique firearm, so long as the ingnition system is the same as the antique, so caplock (sidelock), underhammer, box lock, flintlock, matchlock, wheellock are all antiques, AND the laws where I am prohibit "firearms" in many places, which are not legally the same as "antique firearms".
So, for a bit in the 1990's, bad guys were out stealing cap-n-ball revolvers in burglaries and then using them in robberies, but avoiding "armed robbery with a handgun" charges which hold a heavy penalty. BP guns were considered a "dangerous and deadly device". They finally tightened up the law so if you rob somebody with a Remington 1858 ... it's now robbery with a handgun.
OH and those modern "in-things" used to cheat during muzzleloader hunting season are also considered "firearms" as they aren't copies of original antiques. So for a while guys were getting jammed-up by transporting them to and from the hunting area loaded but without the primer inserted...not realizing that this was still a "loaded" firearm, and when they got stopped by DNR...ooops. Now the law says if you're unprimed, uncapped, or without the primer installed.... you're "unloaded".
And under the law, for a while it would've been legal to hunt in several municipal parks for the geniuses who wrote the laws prohibited hunting with firearms and bows... but said nothing about hunting with antique firearms.
Ever Wonder why my state is called The People's Republic of Maryland??? The place is very anti-gun, and a courageous fellow named Raleigh Boze (sp?) kept taking his flintlock into schools with principal's permission, and kept getting arrested, but the state would always drop the charges to keep from having a judge rule that the law actually says what it says, and he was not in violation... they finally fixed it so it's up to a principal to allow "antique" firearms into the school for a guest lecture or not.
LD