Before I "escaped", to get a rifle, you had to first get a firearms ID card. Finger prints and application and a wait. The whole nine yards.
To get a pistol, it was the same as getting a powder burner, they both are viewed as firearms. You had to apply to the local police and have the chief or one of his underlings sign off on it. That gave you a "permit to purchase" which was good for a time limit, I think it was 60 days. Then you could buy the pistol. I suppose an internet purchase had to go through an FFL just like a powder burner does. The procedure may have gotten worse since I got out, I don't know.
Being the rifle and the pistol are full blown firearms, you technically can't fire them in your basement or yard either. I own a beautiful HW97 that is fully decked out with aftermarkets because my friend was caught shooting it in a backyard under perfectly safe conditions. The only thing that kept him out of jail was the state trooper that responded had some common sense, but told him he would have to cease and desist shooting there hence forth and forever more.
Now, with all the chatter about how powerful these things have become, all it will take is some congress critter to make it his or her mission to make air guns firearms on a federal level and we will all suffer the fate of N.J. and a few other states like it.