I've always been curious how these devices will integrate if at all to existing firearm laws. That's a very bulky and expensive .22, so I would not expect many

I've always been curious how these devices will integrate if at all to existing firearm laws. That's a very bulky and expensive .22, so I would not expect many people to rush out and get one. If some day that same device was equivalent to a 45-70 in 200 to 400 grain pushing 1600 fps and it could hold enough charge for a couple hundred rounds and it was weather-proof and durable, it might get more attention. I would expect to be about as loud as a suppressed powder equivalent and much less pain in the shoulder. But I am more curious how these work legally. Do you need to go through an FFL to get one? If not, will these cause a revamp of firearm laws if and when these devices evolve?