For the ultimate in shooting flexibility, Mossberg’s 590S family of 12-gauge pump-action shotguns are capable of cycling 1.75, 2.75, and 3-inch shotshells interchangeably, in any combination, without the use of an adaptor. Pick one shotshell length for specific shooting needs, or simultaneously load any combination of those shell lengths. The 590S Series includes two full-length stock options and two versions of the bird’s head-gripped Shockwave.
With multiple versions available including optics-ready and Shockwave, there’s a 590S to fit everyone.

We worked with Mossberg to get a 590S pump-action shotgun down to the crew with IraqVeteran8888 for an in-depth review – so let’s break it down!
FROM 590 to 590S: WHAT’S NEW
Based upon Mossberg’s legendary 500 pump-action platform, 590 tactical shotguns include non-binding twin action bars; positive steel-to-steel lock-up and anti-jam elevator; dual extractors; drilled and tapped receivers; and universally-recognized, ambidextrous top-mounted safety. Enhancing the decades-proven 500 platform is a convenient clean-out magazine tube with cap for ease of maintenance. Additional features of the 590S series include black synthetic stock and forend; cylinder bore barrel (AccuChoke™ barrel on the 20-inch version); matte blue metal finish; sling swivel studs; and logo-engraved receiver on all models.
Key design changes of the 590S include a redesigned elevator and bolt slide combined with the addition of an energy-absorbing bumper. This patent-pending innovative platform allows the user to load their choice of shotshell length (1.75, 2.75, and 3-inch) and shotshell type for their specific shooting needs, and in any combination. The use of shorter shell lengths also increases the overall capacity of the 590S.
590S FEATURES
- 12 Gauge Shotgun; 18.5″ or 20″ barrels
- Can cycle 1.75″, 2.75″, or 3″ shells interchangeably–without the need for a short shell adaptor
- Capacities between 5+1 and 13+1 depending on shell size
- Mossberg’s Patented (U.S. Patent No. 11,598,596) design allows the cycling of a range of 12 Ga shell sizes out of the box.
- Traditional 590 features included: Dual Extractors; Twin-action Bars; Ambidextrous Safety; Clean-out Mag Tube
- 590S is also available in two Shockwave models

Standard features on Mossberg Pump-Action Shotguns: Dual extractors, twin action bars, positive steel-to-steel lockup, and anti-jam elevator provide smooth operation. Other features include top-mounted ambidextrous safety, matte blue metal finish, magazine clean-out tube with cap, and a logo-engraved receiver.
590S models cycle 1.75″; 2.75″ or 3″ shells, interchangeably, without the need for an adaptor. Pick one shotshell length, or simultaneously load any combination of the three!
590S AT THE RANGE
The capacity on this shotgun is looney tunes! We kicked it off shooting 14 rounds of mini-shells, 13 in the tube and one in the chamber, which allowed us to get a little more payload downrange with a little more round count. You can see the shells were hitting exactly where I wanted them to hit, tracking very well with the sights.
The sight features a gold bead on the front but you can see that with the 590S, Mossberg has added an optics mount plate designed to run with micro-concealed carry sights, like Trijicon, Crimson Trace, Vortex, and more. A lot of companies are producing micro-carry pistol sights that are made to mount directly to the top of the receiver. That’s definitely one nice feature of the 590S.
You can still mount a traditional rail on top if that’s what you prefer, the patterns for the holes are the same, you’ll just have the plate underneath, which is no big deal.

This is the Mossberg shotgun we all know and love but it can take mini-shells and you’ve got the optics availability. The furniture, the layout of the gun, the bayonet lug – the rest of it is built off the original 590, which is a great shotgun. One thing I will call out is that on this 590S, it’s threaded for chokes as well. So you do have the option to drop in different chokes if you want to.
We used Aguila buckshot ammo for our first shots with the 590S and this 1-3/4 IN | 5/8 OZ | 4B (7P) 1B (4P) is kind of like a candy cane mixture. With that particular load, you’ve got a 5/8 ounce load going at 1200 feet per second so it’s still delivering a good smackdown but you’ve also got 14 rounds in the tube. If you live in a state that has magazine restrictions, the 590S would be a good option to bump up the capacity of your home-defense firearm, which is nice.
While there were some devices available for the 590 previously that you could install to allow shotguns to accept mini-shells, it’s really nice that Mossberg listened to customer demand and redesigned the 590S to accept mini-shells. Not only are they affordable, they allow you to get more shots downrange so it’s a nice option to have on a new shotgun right out of the box.
I think the big selling point of the Mossberg 590S is its ability to accept multiple shells including the mini-shell and the cut for the red dot sight, I think those are really nice features on a pump-action shotgun.
CONCLUSION
During our review, the Mossberg 590S shotgun ran Aguila’s 1 3/4 IN. 5/8 OZ buckshot mini-shells, Broadhead’s hexolit 32 2-3/4″ expanding steel slugs, Federal Premium’s Vital-Shok 3″ magnum load high brass 41-#4 buckshot, and Polyshock’s Urban Tactical IRP 2 3/4″ shotgun round and they all performed well. Along with the threaded barrel for chokes and the ability to easily mount a mini-carry pistol sight, the versatility of this shotgun is truly impressive.

With the addition of the optics mount plate designed to run with micro-sights and the ability to cycle 1.75″; 2.75″ or 3″ shells interchangeably, Mossberg really hit it out of the park with the 590S.
To learn more about this and all models of the Mossberg 590S, visit Mossberg.com!
RELATED CONTENT: Mossberg Launches 940 Pro Tactical Optic-Ready Autoloading Shotgun