Actually I can't see it.
In referencing the Tex. Penal Code 46.01 that you posted,
(3)"...Firearm does not include a firearm that may have, as an integral part, a folding knife blade or other characteristics of weapons made illegal by this chapter and that is:
(A) an antique or curio firearm manufactured before 1899; or
(B) a replica of an antique or curio firearm manufactured before 1899, but only if the replica does not use rim fire or center fire ammunition."
A black powder firearm does not use rim fire or center fire ammunition, and it seems to me would be considered an antique or curio, or replica of an antique or curio.
It looks like there is a clear contradiction between the first and last half of that section of penal code. Because a black powder firearm is "designed, made, or adapted to expel a projectile through a barrel by using the energy generated by an explosion or burning substance," and therfore would be considered illegal to own by a felon. However the Penal Code continues on to say that the term firearm does not include antiques or replicas of antiques that do not use rim fire or center fire ammunition which is in the case of black powder firearms.
I have also researched Federal code and defintions of a firearm. I understand that Federal laws and codes would supercede state laws and codes in the case of a federally convicted felon. An individual convicted of a felony against the United States, would be subject to Federal laws and codes instead of Texas laws and codes foremost, is this correct??
Referencing Title 18, Part 1, Chapter 44, Section 921 of U.S. Code,
(3) The term "firearm" means
(A) any weapon (including a starter gun) which will or is designed to or may readily be
converted to expel a projectile by the action of an explosive;
(B) the frame or receiver of any such weapon;
(C) any firearm muffler or firearm silencer; or
(D) any destructive device. Such term does not include an antique firearm.
(Bold added for reference)
and continues to define...
(16) The term "antique firearm" means-
(A) any firearm (including any firearm with a matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898; or
(B) any replica of any firearm described in subparagraph (A) if such replica-(i) is not designed or redesigned for using rimfire or conventional centerfire fixed
ammunition, or(ii) uses rimfire or conventional centerfire fixed ammunition which is no longer manufactured in the United States and which is not readily available in the ordinary channels of commercial trade; or
(C) any muzzle loading rifle, muzzle loading shotgun, or muzzle loading pistol, which is designed to use black powder, or a black powder substitute, and which cannot use fixed ammunition. For purposes of this subparagraph, the term "antique firearm" shall not include any weapon which incorporates a firearm frame or receiver, any firearm which is converted into a muzzle loading weapon, or any muzzle loading weapon which can be readily converted to fire fixed ammunition by replacing the barrel, bolt, breechblock, or any combination thereof.
(bold added for reference)
As you can see, U.S. Code directly references "black powder firearm."
So my questions still feels un-answered and I will reword it as such...
"Can a federally convicted felon, own a black powder firearm, in Texas? If his conviction was a Federal Felony and not a State of Texas Felony?"
Maybe you can also help me to understand why the similar Texas and U.S. codes seem to contradict themselves?