[Build] Ultimate Mossberg Shockwave: All The Upgrades
Mossberg 590 Shockwave collecting dust? Learn how to upgrade it into a fun, effective, and lightweight range gun with our Ultimate Shockwave build guide.
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What’s one of the most popular new guns in the last ten years?
I’ll give you a hint: It’s mostly just a fun range toy and practically useless outside that niche.
Our mystery gun is also hard to control, deals heavy recoil, and has stoked passionate debate in the tactical community since its release.
Some love it, some hate it, and most cry, “Just upgrade it!” That’s right! Let’s open Door #1 and talk about our friend, the Mossberg 590 Shockwave (full review).
When scouring the internet, you’ll likely come across reviews highlighting the pros and cons of the meme-worthy Shockwave.
But there is one point everyone can agree on: This model can go from greatly useless to remarkably useful with just a few clever upgrades.
My goal when constructing the Ultimate Shockwave build was to improve the original design by making it more effective as a firearm and easier to use.
I also wanted to keep the gun nice and lightweight.
Today, I will run through my upgrade process step-by-step, from braces to grips to slings.
By the time we’re done, you should be able to build your own Ultimate Shockwave. And if you dream up a nifty Frankenwave build of your own while reading, please share it in the comments section!
The Quick List
- Best Brace/Stock Adapter: Ergo Grip Mossberg 500/590 Tactical Stock AdapterJump to Details ↓
- Best Brace: SB Tactical SBA3Jump to Details ↓
- Best Sight Upgrade: XS Sight Systems Big Dot Tritium SightJump to Details ↓
- Best Forend: Ergo Mossberg Forend M-LOKJump to Details ↓
- Best Sling: BFG Vickers ONE SlingJump to Details ↓
Table of Contents
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Is the Shockwave a Firearm or Shotgun?
The Mossberg 590 Shockwave is a unique gun model that benefits from bizarre legal loopholes.
For instance, this powerful and compact firearm is technically not a shotgun—no, not even a short-barreled shotgun!
Per US law, a shotgun is designed to be fired from the shoulder and must have (or previously had—you know, semantics) a stock.
Our Mossberg darling is not equipped with a stock, just a Shockwave Raptor grip.
By this technicality, the Shockwave is legally a close-quarter firearm with the giddy oomph of a shotgun, but in a smaller and more maneuverable package.
As a firearm, the Shockwave is not restricted in barrel length so long as the gun's total overall length is 26” or more. Anything less could be considered a concealable weapon, which is subject to the National Firearms Act.
And that’s the detail I kept in mind when designing the Ultimate Shockwave build.
Best Shockwave Upgrades
Stock Adapter
“Travis,” you might ask. “Surely, the best improvement is to add a stock?”
Absolutely, yes! But remember, that violates the National Firearms Act. We have to keep it legal. We’re upgrading a firearm, not a short-barreled shotgun.
So, let’s talk about the next best thing: adding a stabilizing brace.
A brace allows you to anchor the weapon to your forearm, reducing the recoil and mitigating many of the control issues associated with the original Shockwave design.
I also recommend using an Ergo Grip Mossberg 500/590 Tactical Stock Adapter. It bolts directly onto your Mossberg Shockwave and gives you the ability to equip an AR-15 pistol grip and an AR-15 receiver extension.
For my Ultimate Shockwave build, I added a brace and an old A2 pistol grip that was languishing in storage.
Admittedly, a pistol grip makes the safety less ergonomic, but it’s still reachable with a wide thumb grip.
If you want to keep things simple, SB Tactical sells a 590-SBL Stabilizing Brace Kit complete with adapter, SBL brace, and pistol grip.
The SBL brace can’t be adjusted, but it does the job as a cheap plug and play item until you’re ready to throw more money at your Shockwave.
Brace Yourself with the SBA3
The SB Tactical SBA3 Stabilizing Brace is one of my favorite braces for 12 gauge firearms.
Not only is it slim, sleek, and lightweight, it also allows for five different positions in which to anchor the gun against your wrist or forearm!
Pretty nifty, right?
The SBA3 is very comfortable to use and offers a QD point, making it easy to sling. It can also withstand the recoil of a 12 gauge firearm without any problems.
I know looks aren’t important when it comes to functionality, but I’m spoiled when it comes to my gear, and I find the slim design very appealing.
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XS Sight Systems Big Dot Tritium Sight
Bead sights are easy to use, easy to see, and on a weapon like the Shockwave, they work reasonably well.
But you have better options.
One simple but significant upgrade to the Mossberg Shockwave is swapping out the factory bead for an XS Sight Systems Big Dot Tritium Sight.
Despite its name, this product is roughly the same size as a standard bead and is manufactured with an easy-to-see white ring surrounding a tritium vial.
This unique design functions to improve your sight acquisition speed under any light conditions, day or night.
In other words, you’ll be able to quickly and easily engage your target, even in low light settings.
Good news: The installation process is easy, and the XS package comes with all the necessary parts you’ll need to affix the upgrade to your gun.
Ditch the Factory Pump
I like the idea behind Mossberg’s pump with a strap, but I can’t say I’m a fan of the execution. The screws securing the strap to the pump dig into my hand and cause serious pain whenever I’m firing buckshot loads.
So, I quickly ditched the factory pump for an Ergo Mossberg Forend M-LOK, and I have no regrets to this day.
Check out those M-LOK slots!
It’s cool. It’s handy. What’s not to love?
The Ergo Mossberg Forend M-LOK fits properly on the Shockwave and, despite its all-metal construction, is very compact and lightweight.
Its squarish design also offers a good grip that allows you to manipulate the weapon with confidence.
If you’re planning to use your Shockwave for home defense, you need to equip a trustworthy light.
Lucky for you (and me), this product provides plenty of M-LOK slots to mount lights, lasers, rails, and more to the weapon.
Now, about that light…
Streamlight, You Light Up My Life
There are plenty of light options, and everyone has their favorites. The beauty of the Ultimate Shockwave build is that you can attach a light directly on the M-LOK and get down to business.
For my build, I mounted a Streamlight TLR-1 HL Tactical Flashlight to my Shockwave.
The Streamlight TLR-1 HL is a full-sized tactical weapon light that’s sold in various lumen outputs.
I selected the model with 800-lumens because it’s a powerful little number that’s also compact and lightweight—the two critical elements of my upgrade design.
Plus, it has easy to access controls that work perfectly with my Shockwave setup.
When it comes to home defense, you need a product that’s reliable in a sticky situation.
At 800-lumens, the Streamlight TLR-1 HL is more than bright enough for inside the home, and it can take a serious beating.
If I’m identifying a target in the dark, I trust the Streamlight to keep working after suffering the abuse and recoil of a 12 gauge shot.
Can't ask for more than that!
All About the Grip
You’re going to need a little background information to understand my choice of grip.
I suffer from chronic pain due to a nasty shoulder injury, so I find foregrips to be a bit uncomfortable, especially when it comes to firing pump-action weapons that require repetitive motion.
To mitigate the pain, I tend to prefer angled foregrips and vertical grips on my guns.
The IMI Defense Front Support Grip is an angled foregrip that is both supportive and comfortable to use.
When shooting 12 gauge pump-action weapons, I employ a push-pull method that requires a strong grip to reduce the recoil (and pain). The IMI Defense Front Support Grip facilitates this practice and helps me enjoy a fun day at the range.
While the IMI Defense Front Support Grip is an excellent foregrip, it’s hardly the only product on the market.
A Magpul AFG2 Angled Foregrip could easily fill this role, and BCM makes some awesome stubby grips. The new SIG Tread M-LOK Grip Kit is also a great option.
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The One Sling to Rule My Shockwave
I have a confession to make: I’m a Blue Force Gear Vickers Sling fanatic.
This disclaimer is not an exaggeration; in fact, I factor in the price of a BFG sling whenever I purchase a new gun.
Equip your Ultimate Shockwave with the sling it deserves.
But I promise these slings are worthy of my biased love and devotion. What can I say? BFG has never let me down.
When I got out of the USMC in 2013, I took my BFG Vickers Sling with me as a memento. I used this sling for a good portion of my career, which included a rough year-long deployment.
That sling is now equipped to an AR-15 and still enjoys regular use. Can there be a better endorsement?
When I was plotting my upgrades list, I knew a BSG sling was going to make the cut. And not just any sling, but the ONE Sling, which is aptly named because for my Shockwave, it is the one sling to rule them all.
The One Sling is a 1-inch strip of webbing that’s perfect for a lightweight, versatile, and low-profile build.
This two-point sling is comfortable to wear, weighs 23% less than similar Vickers products, and is equipped with rapidly adjusting pull tabs.
We need to discuss the magical pull tabs.
You can grip or rip the pull tabs to instantly change the length of the sling. For example, it can tighten to the point where you can let go of the gun and use both hands, and then, in a flash, loosen up to a length that maximizes mobility.
What? It’s super cool. Try it and see.
Bonus Round: Your Shockwave Wants the OPSol Mini-Clip 2.0
The last upgrade I made to my Mossberg 590 Shockwave was equipping the OPSol Mini-Clip 2.0.
This adapter is a simple drop-in device that lets your gun feed those adorable 1.75” mini shells with reliable gusto.
It’s an optional upgrade, but certainly worthy of your time and money.
Sure, the factory Shockwave model feeds mini shells well enough without the clip, but it’s hardly dependable or consistent. And it’s incomparable to the joy you’ll experience after installing the OPSol Mini-Clip 2.0.
Want more good news? The installation process is a breeze.
The little wedge drops in easily and is tough enough to take some serious use and abuse.
It’s a simple and ingenious design that works perfectly with the Mossberg 590 series and our Ultimate Shockwave build.
Feel the Shockwave
Ready to start building an Ultimate Shockwave of your own? You won’t regret it!
The construction of the Ultimate Shockwave build started as a mission to make the gun useful, lightweight, and simple to use.
Not to brag, but I think I’ve successfully hit all three targets. The weapon is now easier to handle, more comfortable to shoot, and boy does it pack a formidable punch.
Plus, the weapon is still over 26” in length, so there aren’t any NFA issues to worry about!
Ready to start constructing your own Ultimate Shockwave? What upgrades are you planning? Let us know below.
And if you’re interested in exploring more ideas, check out The Best Mossberg 500 and 590 Upgrades.
Tell us about your upgrade successes and failures (these are fun too!) in the comments.