There are several type of Class 3 items that are restricted by the National Firearms Act.
Each state can impose additional restrictions on the sale, purchase, and transfer of class 3 firearms in addition to the compliance that is required with the national Firearms Act.
In New Jersey you can own the following items that are regulated the the National Firearms Act
Machine Guns *In New Jersey you cannot own the following NFA restricted items.
Any Other Weapon (AOW)
Short Barreled Shotguns (SBS)
Short Barreled Rifles (SBR)
Destructive Devices (DD)
Follow this link to find out more about New Jersey and NFA restrictions on Class 3 Firearms
* Machine guns - Onwership for persons is regulated under N.J.S. 2C:58-5
NOTE: In New Jersey, AOW's are limited