The only diff. between a weapon used at a reenactment & 1 used to kill during the period being recreated is that bullets aren't loaded into a replica weapon. Otherwise, black powder &, occasionally, paper are loaded into the weapon, in a manner consistent with the way a particular weapon was loaded, for real, back in the day.
You can get a replica from any number of online sources that deal in them.
You can, also, get them at gun shows from time to time, but generally gun shows deal in actual, rather than replicated, weapons.