Mossberg’s pump shotguns are durable, reliable, well-made guns that are well known for the use of a tang safety. The safety sits on the top of the receiver in an ambidextrous location that’s easy to reach when using a more traditional shotgun stock. It’s probably Mossberg’s most famous feature, but that’s changing with the Mossberg 590R.
With pistol grips and pistol grip-equipped stocks mixed in, things admittedly got a little more awkward, and it was quite a reach to engage or disengage the safety. That’s changed. If you’re a Mossberg 500 fan but want a pistol grip stock, Mossberg offers the 590R.
The 590R: More Than a New Safety
Gone is the tang safety; in its place sits an ambidextrous lever that works and handles a bit like an AR-15 safety. You’ll notice the stock and pistol grip included aren’t just any old AR stock and adapter. It’s made entirely by Mossberg and integrates a cover for the safety.
This cover is part of the stock and protects the safety to prevent it from being accidentally swept off. The 590R might be new, but the new safety design comes from a 2023 project Mossberg undertook for the British Ministry of Defence—Defence with a C and not an S.
The Ministry of Defence wanted a breaching shotgun that held more than a couple of rounds, but they also wanted an ultra-small gun. It’s not a fighting shotgun, just a niche tool designed for taking doors off their hinges. This led to Mossberg making a breaching shotgun from the 590M series, which uses a magazine.
Breaching shotguns are typically pistol-grip-only guns due to the need to keep them compact. As we covered, the Mossberg’s tang safety makes pistol grips awkward. To satisfy the Brits’ needs, they relocated the safety to the receiver, added a shield over the safety, and bam, the Brits now have a breaching shotgun known as the Vanisher.
Back to the 590R
Mossberg has now taken that same design and given us the 590R and 590RM. The 590R is the model you see here, and the 590RM uses magazines. The folks at Mossberg happily sent me this shotgun to test and review, and as a shotgun aficionado, I was more than happy to sink a few hundred rounds of buckshot through the gun.
Pistol Grip Stocks and Shotguns
I’m a fan of traditional shotgun stocks. Outside of my Benelli M4, every shotgun I own has a conventional stock, typically one with an adjustable length of pull (LOP). While I might not be partial to pistol grip stock combinations, I understand it’s a popular option.
The 590R’s design seems perfect for the new shotgunner transitioning from an AR to a shotgun. The 590R series gives them the stock, the pistol grip, and the safety they are mainly already used to. The magazine models take that a step further.
The stock is right off an AR-type rifle. It’s easily adjustable and covered in sling points. Mossberg used a Magpul grip, and you could replace it with any other AR grip if you so choose.
Mossberg went with an inline stock, which, like an AR, has its benefits. Namely, increased control. The recoil comes straight rearward instead of up and back. This helps keep the gun low and on target between shots.
There is a slight difference when shooting the 590R side by side with a standard 590—muzzle rise is reduced and mitigated a bit.
Shotgun recoil is best mitigated by a push/pull method: press forward on the pump and pull the stock rearward. The vertical pistol grip helps you pull the gun a bit easier and tightly into the shoulder.
The recoil is transmitted more to the wrist, which does become fatiguing. When training, it’s a hassle, but in real life, you aren’t shooting 200 rounds in a self-defense scenario, so it’s not a huge deal.
Getting a Grip
The pistol grip also makes the gun easier to hold up if you have to remove your support hand. It’s easier to keep the shotgun up and on target, or to just safely control. Your spare hand might be needed to reload the gun, open a door, or handle another task.
A downside of the pistol grip-equipped stock and inline design is raising your sights upward. Mossberg equips the gun with Magpul MBUS sights. One is mounted to the included optics rail, and the other is to a Picatinny rail welded to the barrel up front.
These are fine sights, but they are rifle sights on a shotgun. These are made for precise rifle shots, so they slow down shotgun use. I eventually folded the rear sight down and used the front sight while shooting. In reality, your best bet would be to mount a red dot.
Since the sights sit higher, we have one inherent problem: height over bore. It’s not a real problem with most buckshot, but with Federal Flitecontrol, the rounds will appear to hit low at ultra-close ranges. Shotguns are close-range guns, and we typically want our sights sitting low when shooting shotguns. Even a red dot can’t fix this problem.
Blasting Away With the 590R
Let’s talk solely about shooting. The 590’s claim to fame is the safety, and guess what? It works well. It’s easy to hit with the thumb and disengage, and easy to re-engage.
Even though I’ve been a dyed-in-the-wool tang safety fan, I had no problems using this safety. The only issue it provided was the right side safety digging into my trigger finger. Fans of the CZ Scorpion will know what I mean.
The recoiling gun makes the safety dig into my trigger finger. It’s only noticeable with heavy magnum-like loads and full-powered slugs. It wasn’t a problem with 2.75 buckshot in the 1,300 FPS realm, and any birdshot or reduced recoil buck ran pain-free.
The pistol grip and stock combo work well. Adjusting the length of pull on the fly makes it easy to fit the shotgun to your measurements. A super soft recoil pad at the end of the stock helps take the sting out of your shoulder.
You can swap the stock for any other MIL-SPEC AR stock. When doing a proper push/pull, your wrist gets more of the recoil than your shoulder.
The Pistol Grip Difference
The pistol grip design makes driving the gun from target to target a little easier. It helps support the gun’s weight as you move, making it easier to hold up on target. A little less muzzle rise also helps when it comes to multiple targets.
With the 590R and its inline stock, there is less muzzle rise, so you transition more like a rifle: just shoot, drive the gun, shoot again. It’s a neat way to shoot a shotgun; I’m just not used to it. This is a new impulse entirely. My Benelli M4 has a pistol grip, but not an inline stock, so it recoils like a traditional shotgun.
The gun handles like most Mossbergs; the pump has a little slop and grit to it, but it’s still fast and smooth to operate. Mossberg utilizes a newer, smaller pump for this gun. It’s fine and easy to grip and rip.
Mossberg also paired the 590R with an integrated heat shield. It’s not your normal heat shield; it sits a little above the barrel and is fixed via welded points. It’s extremely effective and stays cool. I fired all day in 90-degree temps, and the heat shield was never too hot to touch. It’s nice because sometimes your thumb drifts up a little high while shooting fast and grazes the heat shield.
I aimed to get two full-powered buckshot rounds on target in under a second at 10 yards. This is not a problem with my standard-stocked 590, but I constantly failed with the 590R. I danced around breaking one second at around 1.05 seconds. I think those results revolved around the sights being so high and less intuitive compared to other shotgun sighting options.
More Than The Safety
Mossberg revamped the pump release to work with the pistol grip. It’s an L-shaped lever that sits right above the firing hand thumb. Press it up, and the pump is free.
Mossberg also redesigned the trigger. It’s now a flat-face design that’s stainless. The trigger has a slight take-up and crisp break with a crisp and tactile reset. It’s better than any other shotgun trigger on the market.
The trigger assembly is also metal, much like the 590A1 series. I’m a bit surprised Mossberg used a metal trigger assembly rather than the polymer trigger assembly you see in the majority of the 500 series, outside of the 590A1.
To Pistol Grip or Not To Pistol Grip
I’m still a fan of traditional shotgun stocks. I prefer them, I’m more used to them, and they feel more natural to me. I also started my shooting life with traditional stocks early in life and transitioned to a pistol grip design much later.
I’m not sure if one is objectively better than the other. Each certainly has its benefits. If you want a pistol grip and stock combo, the 590R is the way to go. It’s optimized from the ground up for a pistol grip, not crudely adapted to one.
With a street price of around $800, it’s not a cheap option and is more expensive than most other 590s. You are paying for a new design, and that’s the cost of doing business sometimes.
While I might prefer a traditional stock, if I had to pick a shotgun with a pistol grip and stock design, it would be the 590R. The ergonomics are there, the inline stock has some serious recoil benefits, and the gun is very well made and reliable. With that said, it needs a red dot to meet its full potential.
If that’s not a problem, it’s a solid shooting, easy-handling gun. It has some quirks, but Mossberg delivered on their concept of making a 590 for the pistol grip crowd.
Now, if only they release a run of the British Vanisher breacher guns as AOWs…
