Interesting question, Michael. I’d guess that there might either be an exemption since the movie prop weapons are disabled for use. I’d also wager that the court responded to Marky’s attorney possible request of a waiver when he is using a prop weapon in a movie.
First, there can be no waiver. The law bars such things. And, while a prop firearm may be disabled that is temporary and according to federal law it is still a firearm. And being a firearm under the law it is still a felony for a convicted felon to so much as touch it.