Mossberg 590 Shockwave Firearm – Shooting Tips & Warnings

Mike reviews the Mossberg 590 Shockwave Firearm, NOT Shotgun.

Mossberg 590 Shockwave Firearm
Mossberg 590 Shockwave Firearm

Mike Searson

USA –  -( At 2017’s SHOT Show we got to lay eyes on several new offerings. One of which was the Mossberg 590 Shockwave. This is a unique firearm with a 14″ 12 Gauge barrel and a Shockwave bird’s head pistol grip that gives the firearm an overall length of 26.5″.

It reminded us of the old “Witpro shotguns” used by the US Marshall’s Service and Agents in the Witness Protection program with a few differences.

The “Witpro shotguns” were either AOW (any Other Weapon) or SBS (Short Barreled Shotgun) configurations, had wood furniture, some had choke tubes and sported barrels a bit shorter than 14″. We have seen them as short as 8″ but not usually longer than 12″.

Mossberg 590 Shockwave Firearm

The Mossberg 590 Shockwave, on the other hand is not considered a shotgun under federal law, and therefore has no limit on barrel length. It is considered a firearm and in that regard it need only be over 26″ in length without requiring NFA (National Firearms Act) paperwork and taxes.

According to Federal Law (U.S. Code, Chapter 44, Title 18 § 921):

“The term ‘shotgun’ means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of an explosive to fire through a smooth bore either a number of ball shot or a single projectile for each single pull of the trigger.”

According to Mossberg:

“The Bureau of Alcohol, Tobacco, Firearms & Explosives has confirmed the 590 Shockwave as a “firearm” per the Gun Control Act (GCA), but not a Class 3/NFA firearm. This only speaks to its FEDERAL status. There could be local/state laws that prohibit the sale of this firearm in your state. Consult your State firearm laws for clarification. Just as with any other pistol grip firearm, the buyer must be 21 years of age, and be a resident of the state where s/he is purchasing it.”

The Mossberg 590 Shockwave was never designed to be fired from the shoulder, so it is simply considered a firearm. The Raptor bird’s head pistol grip is uniquely shaped to minimize felt recoil and follows the same design as those used on the Witpro shotguns. These were first designed by scattergun Technologies (bought out by Wilson Combat in the late 90s).

Mossberg 590 Shockwave Raptor Bird's Head Pistol Grip
Mossberg 590 Shockwave Raptor Bird’s Head Pistol Grip
Mossberg 590 Tactical Shotgun (Top) Mossberg 590 Shockwave Grip (Btm)
Mossberg 590 Tactical Shotgun (Top) Mossberg 590 Shockwave Grip (Btm)

The rest of the Mossberg Shockwave follows the lines and materials of the company’s popular 590 tactical shotgun series: ambidextrous top mounted safety, dual extractors, positive steel-to-steel lockup, twin action bars, and a smooth operating anti-jam elevator. The top of the receiver is even drilled and tapped for scope mounting and it is equipped with a brass bead sight.

Technique of the Mossberg 590 Shockwave

Shooting the Mossberg 590 Shockwave is similar to firing a typical shotgun with a stock. Grasp the grip as if it were a standard stock that you are pulling into your shoulder. The difference is that there is no stock to position in your shoulder or to set your cheek against. Still, you need to pull it rearward as if it were a traditional shotgun and sight down the receiver as normal. Just pretend there is a stock there, if you do not get my meaning.

Mossberg 590 Shockwave The Rock Back
Mossberg 590 Shockwave The Rock Back

Your support hand goes through the loop (more on this later) and while pulling back with your firing hand, you push forward with the support hand on the forearm’s slide. Imagine as if you are trying to stretch the firearm in this manner.

When you squeeze the trigger, the 590 Shockwave should recoil rearward and down. Practice this beforehand with dummy rounds or an empty firearm if you must.

If you try to muscle the gun too much or Rambo it, it will more than likely kick you in the face. It may not be the most pleasant way to shoot something in 12 Gauge but it brings a new level of fun to the table.

The 590 Shockwave Loop

Mossberg 590 Shockwave with your hand securely in the loop
Mossberg 590 Shockwave with your hand securely in the loop.

The loop may look different to you and your first inclination might be to cut it off or change out the forend for an AFG, VFG, etc. While adding something of this nature will not affect the legality of the 590 Shockwave (It’s over 26″ so a VFG or the like will not turn it into an AOW), it will affect your shooting technique. If you absolutely hate the loop, I would recommend Magpul’s shotgun forend as an alternative.

Remember, we are pushing forward with the support hand and should your hand let go and end up in front of the muzzle while a round is going off, you might call your support hand “Hamburger Helper” from then on. The Mossberg forend should offer more protection in this regard due to the contour.

Do not change the Raptor grip, either. Adding a traditional (vertical) pistol grip will shorten the overall length making it an AOW. Adding a traditional butt stock will make it an SBS.

Mossberg 590 Shockwave Hamburger Helper Move (DON'T DO THIS)
Mossberg 590 Shockwave Hamburger Helper Move (DON’T DO THIS)

Mind you, if you want either one of those NFA type of firearms, the 590 Shockwave makes for a good base gun upon which to build. Just know that such changes require a Form 1 and a $200 tax.

Mossberg 590 Shockwave Legality

Unfortunately, the Mossberg 590 Shockwave is not legal in all areas. When some states came up with their own Constitutions and fleshed them out with “Weapon Laws” they went a bit further in their definition of a shotgun to include anything that could fire a shotgun shell with a smooth bore barrel or other words of that nature.

We are not just picking on California or a handful of Northeastern states, but places like Texas and Oklahoma. Consult your state’s laws for further clarity.

Just like a shotgun that ships from the factory with a pistol grip or a receiver not yet turned into a firearm, the Mossberg 590 Shockwave can only be purchased by persons over the age of 21.

Mossberg 590 Shockwave The Reality

The Mossberg 590 Shockwave is a niche firearm. This is for a situation that may require more than a handgun, but not quite a long gun. Sometimes it may be better for when space is a premium (horseback, vehicle use, etc.) or you need to worry about excessive range if using a rifle.

It is a tricky firearm for most folks to learn to shoot well, but can be accomplished with practice. However, it makes for a fun range blaster.

We fired 200 rounds of Federal 00 Buckshot without a single hiccup. Patterning was fine and we think that 14” is the optimal barrel length for defensive use of a 12 Gauge.

Our only gripe is that we would have preferred wood furniture and choke tubes, but those are “nice to haves” not “need to haves” on a firearm like this.

So if you always wanted a shorter barreled shotgun, but were too lazy to sign a Form 4, complete a Form 1 or loathe the thought of paying a $200 tax and your state did not try to redefine what a shotgun was; you have an option.

Just don’t make the mistake of referring to it as a shotgun.

It’s just a firearm.

About Mike Searson

Mike Searson’s career as a shooter began as a Marine Rifleman at age 17. He has worked in the firearms industry his entire adult life as a Gunsmith, Ballistician, Consultant, Salesman, Author and was first certified to teach firearms safety in 1989.

Mike has written over 2000 articles for a number of magazines, websites and newsletters including Blade, RECOIL, OFF-GRID, Tactical Officer, SWAT, Tactical World, Gun Digest, and the US Concealed Carry Association as well as AmmoLand Shooting Sports News.

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So I cannot put a pistol grip on this firearm, can I?


The 590 shockwave is not a shotgun? I cannot understand this nonsense. If you take a shotgun and cut it down too short the A.T.F. throws a fit. As the poem goes A rose is still a rose.

John Dunlap

It is nonsense, legal semantics games. My hat is off to Mossberg for finding the loophole in an idiotic, Constitutionally illegal “law” that should have been repealed decades ago, and effectively rubbing Schumer and company’s noses in it.

John R. Blair Jr.

Yep! same happened to me! Shooting 2 3/4 inch # 4 shot I thought MaN that is eating the inside of my thumb. Just like the trigger guard the safety is made of plastic (polymer?) and is secured with a one way non-removable screw!?!?! However, this did not prevent me from using an assortment of abrasive tools to smooth out (off) the SHARP thumb-side edges of the safety. Much better now!!! Someone in Mossberg R&D should take off their shooting gloves when testing. ALSO – the sharp flame melted corners and edges of the pump strap were getting to me… Read more »

Scott Burgamy

Well, I guess I am an idiot but I bought the Mossberg and took it to my brother in laws farm to shoot out in the field. The first shot I fired the safety tore a nice hunk of meat off the back of my thumb. I tried pushing the barrel like I was stretching it for the next few and it was ok. I let my B-I-L try it and I tried to tell him how to hold it and it tore a piece of meat off him as well. Maybe they should have a You Tube video showing… Read more »


Yep! same happened to me! Shooting 2 3/4 inch # 4 shot I thought MaN that is eating the inside of my thumb. Just like the trigger guard the safety is made of plastic (polymer?) and is secured with a one way non-removable screw!?!?! However, this did not prevent me from using an assortment of abrasive tools to smooth out (off) the SHARP thumb – busting edges of the safety. Much better now!!! ALSO – the SHARP melted nylon corners and edges of the pump strap were getting to me so I reversed the ends to facing out instead of… Read more »

Mike B

What about adding a Knoxx Breacher Grip? Firearm still exceeds 26″. So, wouldn’t it be legal?

Brandon Petrucci

I’ve been wondering this does it still exceed 26 if you add that ??

James Normand

Hi. I just purchased a Shockwave and tried to affix a flashlight with no luck. The assembly purchased could not find a home on the barrel.
For home defense, thought a side flashlight would be handy for both close range target acquisition and safety. Any thoughts?


GGG-2007 mini rail mounts on the end of the shell tube. Works great. Order from GGG themselves (


Got one 8/25/17 Van’s deer processing Brandon MS. Looking for the Aguila 1 3/4 – inch 12 gauge no. 4 buck mini-shell; which seem to be SOLD OUT, have the OPSol mini-Clip (Texas product!) on order… Excited!!!!

Jim Engle

These are now selling in Ohio in the local shops. I just picked up a Rem TAC-14 yesterday. I’ve always been a fan of the Remington 870 design.


I just ordered the Mossberg Shockwave for September 1st pickup in Austin TX.


I’m in Texas as well just picked up one from Saxet gun show today

Sgt Bubba

Never was a Mossberg fan. Taught firearms at police academy for years was our departments firearms instructor for 25 yrs and used only Remington 870 or 1100’s. I have 11 old 870 in safe now. Bought a new 1100 competition and had so many problems with it, I sent it back to Remington only to have them say I abused it after 25 rds. They wanted $200 to make it go “BANG”. What they did was ruin 55 yrs of faithful customer loyality. Give me the Mossberg……I won’t buy a new Smith and Wesson, Remington or Marlin the quality control… Read more »


The Magpul forend will NOT fit the Shockwave, w/o also replacing the action tube assembly. From the Brownells website:
The MOE Forend for Mossberg is a simple, lightweight forend for the Mossberg 500/590/590A1 lines of 12 gauge shotguns with the 7-5/8″ action tube assemblies – it will NOT fit the Mossberg 500 shotguns with 6-1/2″ action tube assemblies

steve smitty

The ERGO tri-rail 606 forend will fit but very tight. Model 4865-short. I greased tube and forend with light mineral oil and hammered in place with a rubber mallet, correcting for fit as I went. Super result and mounted Streamlight with laser and side folding UTG aluminum grip, like a Sten magizine off to the side. Works perfect and folds out of the way. Awesome setup and very happy with it. I had heard of loosening and failures of plastic forends, so I paid the extra and bought the ERGO.

steve smitty

Typo, I meant tri-rail 606(1) as in 60601 alumimum.

Lee Major

Hello guys, just to be clear, if I change the raptor grip to a pistol grip I have to pay $200 or can I simply pay the $5 tax stamp fee for that?

Big Bill

Lee, the grip, bu itself, isn’t what makes it legal or illegal. In this case, as I understand it, it’s the fact that the weapon isn’t a shotgun, because it doesn’t have a buttstock (and never had one), and its overall length is over 26″. If a pistol grip brings it under 26″, then you may well run afoul of the BATFE(and really big fires). However, I have a Mossberg 500 ‘convertable’ (came with both buttstock and pistol grip) with a 18.5″ bbl, and got a Raptor grip, installed it (still over 26″), and, IMO, the Raptor has it all… Read more »


I just purchased a Shockwave in the Chattanooga Tennessee area. I like the gun with magnum loads you better have a good hold on it. This is the first I have read about how to hold it, I will try this way tomorrow. I would like the grip angle to be closer to a pistol grip something like a butt stock on a match grade rifle.


I was just wondering if you did make a mistake and called the Shock wave a shotgun would your genitals fall off. As you can probably tell I am not a big fan of Oduchbags ATF.
A Retired LEO

Isaac Arnold

Before September 1, 2017, the Shockwave is probably not legal in Texas, but after September 1 it will be.

Matt in Oklahoma

Props to the author for putting out the state laws!!
Mossberg failed to do so in their rush to sell and advertise.
Don’t do it in Oklahoma.


Remington also released a 14′ barreled shotgun, the Tac 14… No mention of state laws with them either. Kudos to the author !


The drilled & tapped receiver allows the mounting of a section of picatinny rail (I found for $8, delivered!, on eBay). Then on the rail you could mount a light or a laser designator to assist in aiming, or a reflex sight too. The Mossberg also is easier to use with the short Aguila mini-shells, with the OpSol adaptor.


Unfortunately, not legal in Ohio.


Waiting for them to make one based on their autoloader! !!


Remington just did!

Clark Kent

Better yet, ditch the Mossberg with its aluminum receiver and buy a Remington 870 with a steel receiver. Makes a world of difference when shooting buckshot. Your body will thank you.

Rod Klomp

The Shock Wave is a 590, it has a steel receiver , the 500 is aluminum, so I’m told..

Big Bill

No, the 590 has an aluminum receiver, as does the 590A1.
The extra weight of a steel receiver is minimal; 8 oz heavier for the Remington, similarly equipped. A half pound difference in a 7+pound shotgun isn’t much, at least to me. But I’m a big guy; maybe to a smaller person it would make a difference.

Rod Klomp

Interesting, I got this info from my LGS, I saw and handled one, it felt pretty heavy, so I had no reason to doubt him, I have a Remington 870 tactical , ghost sights and tactical mussel brake, I prefer the safety location of the 870 over the 500 Mosberg. I’m a big guy also, so a little weight isn’t a problem, thanks for the heads up Big Bill, much appreciated…

Reggie H

Remington hasnt made a decent gun in 12 years. QC sucks with freedom group.


True Story, Remingtons QC has went to CRAP!
Bought a 700 P in 300 win mag, reamer burrs in the throat, long story short, took 8 months to resolve, and remington replaced it with another bum gun with defects!! Im done with remington.
I love the controls on mossbergs way better anyways.


I agree in terms of recoil. To me, the Mossberg with the tang safety and the drilled and tapped receiver wins out. Put on a Magpul m-lok forend with stop, and you have a lot more possibilities. Not arguing, just my two cents.


I have had both, still have the Mossberg….. I’ll take the Mossberg over the Remington, The bolt lockup is with the barrel NOT the aluminum receiver so that point is completely mute. No rust to deal with, you may wear the finish off of the receiver of the Mossberg, but it won’t rust or pit. The Mossberg extractor can be replaced quickly if broken without drilling, picked by the military over the Remington. Win, Win with the Mossberg over the Remington. Add to this the Remington name and quality have taken a big dive in the past years. The parent… Read more »


Steel or aluminum……does a magnet stick to it?

Big Bill

Steel or aluminum? If you mean the receiver, it’s aluminum on the Mossberg, steel on the Remington.
This makes trhe Remington heavier, but prone to rust. While steel is stronger than aluminum, no one has demonstrated that this is a weakness in this application. Unless you use the gun as a club, it doesn’t matter, and probably not even then.