Is the Mossberg “590® Shockwave” Legal in New Jersey?

Yes.

N.J.S. 2C:39-1f.  Defines “Firearm” as follows:

"Firearm" means any handgun, rifle, shotgun, machine gun, automatic or semi-automatic rifle, or any gun, device or instrument in the nature of a weapon from which may be fired or ejected any solid projectable ball, slug, pellet, missile or bullet, or any gas, vapor or other noxious thing, by means of a cartridge or shell or by the action of an explosive or the igniting of flammable or explosive substances.  It shall also include, without limitation, any firearm which is in the nature of an air gun, spring gun or pistol or other weapon of a similar nature in which the propelling force is a spring, elastic band, carbon dioxide, compressed or other gas or vapor, air or compressed air, or is ignited by compressed air, and ejecting a bullet or missile smaller than three-eighths of an inch in diameter, with sufficient force to injure a person." (Emphasis added)
 
The 590® Shockwave is plainly a “Firearm” under NJ Gun Law.

No.

N.J.S. 2C:39-1n.  Defines “Shotgun” as follows:
 
"Shotgun" means any firearm designed to be fired from the shoulder and using the energy of the explosive in a fixed shotgun shell to fire through a smooth bore either a number of ball shots or a single projectile for each pull of the trigger, or any firearm designed to be fired from the shoulder which does not fire fixed ammunition." (Emphasis added)

The 590® Shockwave is not a “Shotgun” under NJ Gun Law because it is not shoulder fired. It is designed to be fired with two hands.

No.

N.J.S. 2C:39-1k.  Defines “Handgun” as follows:

"Handgun" means any pistol, revolver or other firearm originally designed or manufactured to be fired by the use of a single hand." (Emphasis added)

The 590® Shockwave is not a “Handgun” under NJ Gun Law because it is not fired with a single hand. It is designed to be fired with two hands.

Yes.

N.J.S. 2C:39-1r.  Defines “Weapon” as follows:
 
"Weapon" means anything readily capable of lethal use or of inflicting serious bodily injury.  The term includes, but is not limited to, all (1) firearms, even though not loaded or lacking a clip or other component to render them immediately operable; (2) components which can be readily assembled into a weapon; (3) gravity knives, switchblade knives, daggers, dirks, stilettos, or other dangerous knives, billies, blackjacks, bludgeons, metal knuckles, sandclubs, slingshots, cesti or similar leather bands studded with metal filings or razor blades imbedded in wood; and (4) stun guns; and any weapon or other device which projects, releases, or emits tear gas or any other substance intended to produce temporary physical discomfort or permanent injury through being vaporized or otherwise dispensed in the air." (Emphasis added)

The 590® Shockwave is a “Weapon” under NJ Gun Law because it is capable of lethal use and because it is a firearm.

No.

N.J.S. 2C:39-1o.  Defines “Sawed-off shotgun” as follows:

"Sawed-off shotgun" means any shotgun having a barrel or barrels of less than 18 inches in length measured from the breech to the muzzle, or a rifle having a barrel or barrels of less than 16 inches in length measured from the breech to the muzzle, or any firearm made from a rifle or a shotgun, whether by alteration, or otherwise, if such firearm as modified has an overall length of less than 26 inches. (Emphasis added)

The 590® Shockwave is NOT a “Sawed-off shotgun” under NJ Gun Law because it is not a shotgun, it is not made from a shotgun and it is over 26” in overall length.

Yes.

N.J.S. 2C:39-1c.  Defines “Destructive device” as follows:

"Destructive device" means any device, instrument or object designed to explode or produce uncontrolled combustion, including (1) any explosive or incendiary bomb, mine or grenade; (2) any rocket having a propellant charge of more than four ounces or any missile having an explosive or incendiary charge of more than one-quarter of an ounce; (3) any weapon capable of firing a projectile of a caliber greater than 60 caliber, except a shotgun or shotgun ammunition generally recognized as suitable for sporting purposes; (4) any Molotov cocktail or other device consisting of a breakable container containing flammable liquid and having a wick or similar device capable of being ignited.  The term does not include any device manufactured for the purpose of illumination, distress signaling, line-throwing, safety or similar purposes. (Emphasis added)

The 590® Shockwave is a “Destructive device” under NJ Gun Law because it is capable of firing a projectile greater than .60 Caliber (12 Gauge = .729 Caliber) and it is NOT a shotgun. Note: The "...or shotgun ammunition generally recognized as suitable for sporting purposes..." (Emphasis added) provision applies to the ammunition itself. Many misread this and think as long as the weapon fires shotgun ammunition it is okay, it is not. This is in the statute so that shotgun ammunition itself does not fall under the definition of a Destructive Device and be regarded, for example,  as a bomb, mine, or grenade.

Conclusion: The 590® Shockwave is therefore prohibited in New Jersey as a “Destructive device” under N.J.S. 2C:39-3a. This statute states: “Any person who knowingly has in his possession any destructive device is guilty of a crime of the third degree.”  It carries a maximum State Prison sentence of 5 years.

UPDATE:  An email was recently sent out to FFLs in New Jersey with a message from “THE NJSP FIREARMS INVESTIGATION UNIT.” It stated “…Mossberg Model 590 Shockwave, Black Aces Tactical DT and the Remington TAC-14. The New Jersey State Police Firearms Investigation Unit concurs with the Bureau of Alcohol Tobacco and Firearms (BATF) that these pistol grip only designed firearms are legal for sale in the State of New Jersey as a firearm.”
​I respectfully believe the NJSP are wrong. See my article here.