In NJ the only Class 3 you can theoretically have is a machine gun. All other Class 3 is is illegal and no permit exists for them. I wonder if you can have an SBR machine gun? But everyone above is right you won't realistically get the permit.
I have mostly non-sporting firearms
In NJ, technically speaking, ALL guns are illegal
Also in my state there is such thing as a Class III BB gun :barf:
Happy to say that despite the NJ AWB I still manage to make my guns look scary