The M-1 carbine is illegal to even own in NJ. I don't know about the M-2. The M-1 Garand is legal, though -- for now.
There is a bill to ban the .50 cal. in the state, as well.
The M-2 is a machine gun. In theory it is legal with the proper permit to own a machine gun ... but per Knappen II p.275 [a guide book on NJ's asinine gun laws] in reality there is no way to obtain the necessary permit and even if you did obtain permit would only be good to two years.