[marktwain]

(C) a short-barrel firearm??????????...............

Texas, as with many states, copied Federal bans on short barreled rifles and shotguns into its state law.

My belief is they were lobbied to do so so as to prevent challenges to the National Firearms Act.

The NFA is irrational and may not stand a Supreme Court challenge, particularly now with Gorsuch and Kavanagh on the Court.

[Lurkinanloomin]

I would not count too heavily on Kavanaugh.
To him precedent is king.
I don’t foresee him overturning much.

[Centurion2000]

Texas, as with many states, copied Federal bans on short barreled rifles and shotguns into its state law.

You are complete mistaken on this. SBS (short shotguns) and SBRs (short barreled rifles) are completely legal in the state of Texas.