Not a "firearm"
Under United States law, a black powder pistol is not a firearm. Directly from the ATF's web site - https://www.atf.gov/file/61721/download [pdf] -
... a muzzle loading weapon that meets the definition of an “antique firearm” is not a firearm ...See 18 U.S.C. § 845(a)(5)
The definition is cast pretty broadly. It doesn't have to be old, it just has to use black powder. The regulations also state that black powder and musket balls don't count as "ammunition". So disorderly conduct is about all they can get him on, since he can't be accused of discharging a firearm in public.
Biting the hand that feeds IT
