Why does Mossberg produce both a 500 model and a 590 model? It’s easy to say the 590 is just the tactical version, but that’s not the whole truth. The 500 has a variety of tactical models, so why is there a 590? It’s because of the United States military. This brings us to today’s article, which focuses on five fascinating facts about the Mossberg 590.
Mossberg 590 Trivia Time
1. The Origin of the 590
Since World War I, the United States military has always had a smorgasbord of shotguns. In the late 1980s, military shotguns included the Ithaca 37, the Remington 870, the Winchester Model 12, and the Winchester Model 1200. Unlike rifles and handguns, there wasn’t a big push to standardize the service shotgun.
Shotguns have always been niche military weapons, but in 1987, the military wanted to standardize the service shotgun, or at least attempt to. They put out a call to gun manufacturers, and Mossberg responded with the 500. The 500 didn’t meet a requirement for the magazine tube. The military wanted to be able to remove the magazine cap, and the magazine cap of the Mossberg attached to the barrel.
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Mossberg made modifications and released a model of the 500 with a removable magazine cap, which would become the M500 in military parlance, but Mossberg designated it the 590. It’s kind of like how the Beretta 92FS is the M9. It’s just a little more confusing since the Mossberg 500 exists and isn’t a 590.
2. How the 500 Became the 590
Why did Mossberg add 90 to the name? What’s the naming convention Mossberg was trying to follow? Mossberg hasn’t produced another shotgun with a 90 designator until 2025 with the 990 Aftershock, but the 90 there is just a reference to the 590.
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The 90 designation came from the military’s initial order of the M500 shotguns. These pre-590 590s featured the 590 design. They ordered 5,900 of these shotguns. Mossberg dropped a zero from this number and named it the 590 as a reference to this initial order.
3. The 590A1 and Tighter Patterns
I first heard this from Steve Fisher of Sentinel Concepts. He talked about how the 590A1 threw tighter patterns than a 500, standard 590, or other similar shotguns. We know shot spread is controlled by things like the choke, the wad, the amount of shot, and more. Mr. Fisher theorizes that the heavy-walled barrel and bayonet lug affect barrel harmonics.
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This results in a tighter pattern. After hearing this, I had to test it for myself. I took out a 590A1 and a Mossberg 500, both cylinder bore guns, and fired the cheapest buckshot I had through each. The Mossberg 500 produced 11-inch patterns at 10 yards. The 590A1 produced 7.5-inch groups at 10 yards. That’s a substantially tighter pattern that’s proven to be a consistent theme with the 590A1.
4. It’s the Only Shotgun to Pass Mil-Spec 3443E
The military is big on tests and testing, and the test for, quote, “Manually operated, slide-action, hammerless, 12-gauge riot-type shotguns” is called the 3443E, which has been updated to the 3443G. The test set the requirements for the new shotgun and also defined the durability and reliability requirements a shotgun must meet to be accepted for use by the U.S. Armed Forces.
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The main part of the test worth noting is the torture test. It requires a shotgun to fire 3,000 rounds of full-powered buckshot with no more than three malfunctions and no parts failure. The Mossberg 590 and 590A1 are the only shotguns to have ever successfully passed the demanding Mil-Spec 3443E test.
5. A 590A2 Exists (Kind Of)
The Mossberg 590A1 is well known, but did you know a 590A2 exists, kind of? The military designation is the M500A2, and remember the 590 is the M500 in military parlance. The M500A2 is a 590A1 fit with the Military Enhancement Kit, or MEK.
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The Marine Corps is the only branch that has fielded the 500A2 and has only done so in small numbers with Fleet Antiterrorism, Recon, and similar small teams. The M500A2 with MEK integrates three different stock options: the Rigid fixed stock, the collapsible stock variant, and the pistol grip-only design.
Another part of the MEK is the presence of a breaching device at the end of the barrel. This allows the gun to be placed against locks and hinges without worrying about damaging the barrel. This breaching device has teeth to bite into the door and provide a stable point for firing breaching rounds in various positions.
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The 590 Forever
The 590 isn’t going anywhere anytime soon. It’s expanded into .410 and 20-gauge variants, and it’s Mossberg’s flagship fighting shotgun. It’s a tank of a gun and one of my all-time favorite pump-action shotguns.
