Very True in Virginia. Any device originally designed to launch a projectile by explosives means is a firearm in Virginia.
A pre-1898 firearm may not come under the authority of the 1968 Gun Control Act but if it fits the description above, it's still a firearm in Virginia.
So while you can order a black powder cap & ball revolver and have it shipped to your front door (in Virginia) without any FFL involved; you cannot legally possess that cap & ball revolver if you're convicted felon.
If you use that cap & ball revolver (or muzzleloader rifle, shotgun , etc.) to commit a robbery; that will be "use of a firearm in the commission of a felony" (at least in Va.)
If you possess that cap & ball revolver while selling cocaine or meth you will be committing the crime of simultaneous possession of a firearm and illegal drugs.
If you carry that cap & ball revolver onto school property it will be considered a "firearm"
The examples go on but you get the point.
Just because federal law may permit some activity doesn't automatically mean the state cannot prohibit that same activity.