Mossberg Model 590A1 Magpul Nine-Shot 12 Gauge Pump-Action Fighting Shotgun

by Jeff Quinn

photography by Jeff Quinn & Boge Quinn

December 1st, 2014


Click pictures for a larger version.











Bayonet lug.





Slide release.









Mossberg has been making the basic Model 500 shotgun for over fifty years now. The 500 has proven itself to be an excellent shotgun, for both sporting and fighting purposes. The 500 design has broadened over the years into other versions, including the 535 and 835 sporting guns, and the 590 fighting shotgun. In business since 1892, Mossberg has always been known for providing good guns for the working man, and the number of Model 500 series shotguns produced exceeds ten million.

While Mossberg has always served the sportsman with reliable, affordable firearms, here, we are looking at Mossberg's shotguns that are built for fighting. For that purpose, Mossberg offers a variety of choices, and all of them are good, but there are differences. The Model 88 is their entry level imported shotgun. It uses a triggerguard safety, so unless one just has to have the lowest-priced shotgun, I recommend moving up to at least the Model 500. While utilizing the same basic, proven design, there are differences between the Models 500, 590, and 590A1 shotguns. Each of them loads easily, with the shell lifter completely out of the way while loading. They have smooth pump actions, utilizing twin action bars. They have durable aluminum receivers, with the bolt locking into the steel barrel extension, and each will function with  2 3/4 or 3 inch shotshells.  The Model 590A1 is Mossberg's heavy-duty fighting shotgun. It is pretty much the shotgun that is in use by our military, and is a beefed-up Model 590. The 590/590A1 pump guns have a different magazine tube/barrel system than does the 500, allowing for the addition of a magazine extension, if desired, and also allows for easier cleaning on the inside of the magazine tube. On the 500, 590, and 590A1 series shotguns, the safety is exactly where it should be; atop the receiver. To me, this is much superior to a safety on the trigger guard, and works equally well for both right-handed and left-handed shooters. On the 500 and 590 shotguns, the safety button is plastic. On the 590A1, the safety button is of the same design, but it is made of metal. The trigger guard on the 500 and 590 shotguns are also made of plastic, but is aluminum on the 590A1. Instead of blued steel and anodized aluminum, the 590A1 has a Parkerized (phosphate) finish, for better corrosion protection. Finally, the barrel of the 590A1 is a heavier, thicker-walled tube, built heavier for greater durability. The 590A1 is one of the best fighting shotguns ever built.

Like the other Mossberg fighting shotguns, the 590A1 is offered with a choice of stock designs, with the one shown here wearing a Magpul stock, forend, and accessories. The Model 51773 shown here wears a twenty-inch, heavy-walled, cylinder bore (no choke)  barrel. The magazine holds eight 2 3/4 inch shells or seven 3 inch shells. The buttstock is Magpul's adjustable unit, which has removable spacers to adjust for length-of-pull (LOP). The LOP is adjustable from approximately 12.25 inches to 14.25 inches. I like mine set at about 13.25 inches on a fighting shotgun, so I removed two of the spacers. I might even remove one more. The recoil pad is a soft synthetic rubber, and it works really well to take the pain out of shooting maximum loads. The forend is a well-textured synthetic unit, with front and rear hand stops. It is very comfortable to use, and can be fitted with accessory rails, if desired. The magazine tube is fitted with a bayonet lug, should you choose to fit a bayonet to your shotgun. The standard issue US M9 bayonet fits perfectly and attaches quickly. Just in front of the bayonet lug is a sling attachment that supports the barrel and mag tube. At the rear of the receiver is another sling attachment point that can be switched from one side to the other, as desired. On both sides of the buttstock are additional sling attachment points. The Magpul buttstock also comes with two cheek-pieces of differing heights. I installed the taller one, as it places my eye higher, and better-suits the way in which I aim the shotgun.

The sights shown pictured on this shotgun in the are not the correct sights for the current Magpul 590A1. This is an early-production shotgun, and the sights have been upgraded on the current-production model. The sights shown attached to this particular shotgun are standard on the Magpul 590. The sights now installed on this 51773 Model Magpul 590A1 are better. They include a rear Picatinny rail, and XS Sights Ghost Ring Sight System, shown in a picture here. The 51773 Magpul 590A1 shotgun has an overall length of  39.625 inches (depending upon spacers used), and weighs in at seven pounds, fifteen ounces on my scale. It is a heavy-duty pump action shotgun, built for serious purposes.

I fired the 590A1 shotgun with every type and brand of 12 gauge ammo available to me, including light target loads, heavy field loads, buckshot, and magnum slugs. The Mossberg functioned perfectly and smoothly with everything. Every shell loaded, fed, fired, and ejected perfectly. The trigger pull is pretty crisp, just about perfect for such a weapon, releasing with about five and one-quarter pounds of resistance. The shotgun handles well, and feels like a heavy-duty shotgun, with enough heft to attenuate recoil, but not so heavy nor bulky as to hinder handling in tight quarters. I really like the shape of the pistol grip on the Magpul buttstock. It allows the weapon to be handled one-handed, if necessary, yet does not hinder the access to the safety, as would a full pistol grip.

For some defensive and offensive situations, the shotgun is superior to both the handgun and the rifle, with devastating power. In close to moderate range fighting, the shotgun offers a real power advantage over a handgun. Only in the tightest of quarters would the length of a shotgun be a disadvantage, but inside or outside a home, in a defensive situation, the shotgun rules, and the Mossberg 590A1 is one of the best ever built for such a purpose. I highly recommend this Mossberg 590A1 Magpul version.

As of the date of this review, the Mossberg 590A1 Magpul shotgun, Model 51773, has a suggested retail price of $855 US.

Check out the extensive line of Mossberg firearms and accessories online at

For the location of a Mossberg dealer near you, click on the DEALER FINDER at

To order the 590A1 Magpul shotgun online, click on the GUN GENIE at

To order quality shotgun ammunition online, go to and

Jeff Quinn

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Click pictures for a larger version.



Magpul adjustable buttstock.





590A1 as tested is an early-production gun; this picture shows upgraded XS sights used on the current-production version.



Three of the many loads tested in the 590A1.



Two shells of nine-pellet buckshot at fifteen yards (top), and a single nine-pellet buckshot load at five yards (bottom), show prefect defensive spread pattern.