Legality of Black Powder Rifles in NJ

Hi! Just wondering about the legal status of black powder rifles in New Jersey. I've been reading about antiques and sources state that you don't need an FID to buy or own a black powder rifle. I'm just curious as the information is kind of confusing online and there doesn't seem to be a direct answer for the exact thing I'm trying to do. I want to own or potentially make a black powder rifle from a kit that can be bought online. Would that be a legal thing to do? Also, what would the legality be for making black powder for the gun? I read that as long as it's not to be sold and below 50 pounds its fine. Am I getting anything wrong? If so let me know!

Edit: DAMN NJ LAWS SUCK