More than 10 million Mossberg 500 shotguns have been made since the first one was produced in 1960. They have ridden in police cruisers throughout the U.S., and in Jeeps and Humvees during the Gulf War and the Iraq War. They’ve been slung over the shoulders of waterfowlers, turkey hunters, and deer hunters.
Why have they been so popular? Several reasons: The 500 is a simple, no-frills shotgun. It’s affordable. It appeals to shooters who prefer a tough, functional gun rather than something prettier and more refined. But the biggest reason for its longevity is its balance of adaptability and consistency. And to understand where that manufacturing philosophy came from, you have to know a little bit about the company and the man who started it.
Mossberg, the Man
Oscar Frederick Mossberg was born in 1866 in Sweden and immigrated to the U.S. when he was 20 years old. His friend and countryman, Iver Johnson, offered him a job at the Iver Johnson Arms & Cycle Works in Massachusetts and introduced the young man to the world of firearms for the first time. He would never leave it.
Mossberg supervised the manufacture of revolvers and shotguns at the plant. He contributed some of his own designs, including a top strap latching mechanism for the Iver Johnson Safety Revolver.
Mossberg bounced around the gun manufacturing world for a bit. He left Iver Johnson and went on to manage the factory of C.S. Shattuck Arms Co. in Hatfield, Massachusetts, a company that made single and double-barrel breechloading shotguns. After that, Mossberg went to work for J. Stevens Arms & Tool Co.
In 1914, Mossberg left Stevens and moved to New Haven, Connecticut to work for Marlin-Rockwell, which was humming with the production of machine guns for the front lines of World War I. When the company went out of business after the war, the 53-year-old Mossberg and his two sons Iver and Harold started a gun company of their own: O.F. Mossberg & Sons.
Once he established his own company, Mossberg and his sons began work on a simple four-shot .22LR pistol dubbed the Mossberg Brownie. It was basically a cross between a derringer and a pepperbox pistol with four barrels, a double-action trigger, and rotating firing pin. When the trigger was pulled, it cocked and released the hammer, as well as rotating the firing pin to fire each chamber in succession.
It was billed as “just the thing to finish trapped animals”—a gun built for function. They produced about 37,000 Brownie pistols between 1920 and 1932—not bad for something that started out as a novelty pistol. Today, a Mossberg Brownie goes for about $400 in mint condition. It sold for between $5 and $10 new.
The Brownie allowed Mossberg’s new company to grow steadily, and he eventually purchased a building in New Haven, Connecticut to house the business. In 1922, Mossberg introduced the first of a new line of .22 LR rifles that were pump-action repeaters designed by Arthur E. Savage, the son of the owner of Savage Arms Cops.
In 1937 Mossberg built a third factory in New Haven, producing simple and affordable guns for the broad civilian market. After Oscar Mossberg passed away in 1937, his son Harold took the helm. During this period, the company diversified its offerings, producing rifles, shotguns, and pistols.
When World War II came, Mossberg shifted its market focus from 27 percent military to 100 percent, and the company added 200 employees. That created a 500-person workforce clocking in for three shifts, 24 hours a day, to churn out parts for Browning M2 .50-caliber heavy machine guns and for the Enfield No. 4 rifle, as well as the U.S. Model 42, and Model 44 .22 caliber bolt-action rifle, used for early small arms training in the Army and Navy.
After the war and through the 1950s, Mossberg made a line of .22 LR target and sporting rifles for entry-level hunters and target shooters. During that time, the company expanded to bolt-action and pump-action shotgun designs.
In 1960, the company shifted production to a new facility a few miles away, and in August of the following year, produced the very first Mossberg 500 pump-action shotgun.
A Robust Shotgun
The M500 was by no means the company’s first shotgun. In 1955 the company began producing the 200 Series, which was an innovative but odd-looking two-round magazine-fed, pump-action shotgun that featured a number of innovations. The 200K model had a C-Lect adjustable choke, while the 200D had an interchangeable choke system and an indicator that let the user know if a round was chambered and the hammer was cocked. It also had a nylon forehand that housed the two tracks on which the slide traveled.
The Model 500 was designed by Carl Benson, the company’s lead design engineer, and was originally intended to be a 12-gauge shotgun for the beginning hunter, but its uses quickly expanded after the shotgun was introduced in 1960.
The gun was made with as few parts as possible, and could be produced easily with less machining than pump guns of the day. It required no hand-fitting, which saved on production time and costs. This translated into an extremely affordable shotgun that just about anyone could own. It also meant the shotgun was particularly robust and could take a beating in the field and still function.
These simple yet powerful attributes would make various versions of the M500 the go-to shotgun for hunters, law enforcement officers, and soldiers for decades to come.
Easy to Disassemble
When you disassemble a Mossberg 500, the first thing you notice is how basic the parts are. There are no tiny detent springs or little roll pins, no assemblies of small parts that you have to take photos of so you remember how they should be positioned. Other than a punch to pop out the pins that hold the trigger assembly in place, it can mostly be taken apart with your bare hands.
The other thing you notice, even though the receiver is streamlined and not at all bulky, is all the room inside around the action bars, elevator and other components.
This means the moving parts don’t rub on the inside of the aluminum receiver, reducing wear. It also means that the components have plenty of room to function in the presence of dirt and debris—a big plus for waterfowlers and other hunters, and a huge benefit in combat, but we’ll get to that later.
While barrels, stocks, grips, and sights for the Mossberg 500 are many and varied, the receiver and action is pretty much the same on every version, save for differences in chamber length. The M500 has an anodized aluminum receiver and steel bolt that locks into a steel extension of the barrel, which is and always has been interchangeable.
The fact that users could swap out barrels in a few seconds without going to a gunsmith meant one shotgun could serve various functions simply by purchasing additional barrels and chokes, scoring big points with hunters on a budget.
One feature that made it so easy to swap out barrels on a Mossberg 500 is the design of the magazine tube. As with most pump guns, the magazine tube is located beneath the barrel and is screwed directly into the receiver. One large locking lug is used to secure the breech. The mag tube is closed at the muzzle end, with the barrel held in place by a bolt attached to its underside that screws into a hole machined into the end of the mag tube.
To remove the barrel from the receiver, all you have to do is unscrew the bolt. The downside is that because the bolt is attached to the barrel at a fixed point, a given barrel can only accommodate a specific magazine tube length. For example, a barrel made for a 6-shot magazine tube won’t fit a gun with a 4-shot or 8-shot mag tube.
One feature carried over from the 200 series is the distinctive safety located on the tang. On the 200 it was a tab that flipped left to right, while on the M500 it was changed to a tab that moved forward and rearward. You operate it with your thumb, and that feature makes the shotgun inherently ambidextrous. (The slide release lever is located on the left side of the gun in front of the trigger, but lefties can still activate it with their trigger finger when necessary. And, there’s a fix for it.)
The only flaw of the original M500 design was its single action bar. On the earliest models, the lone action bar could occasionally bind or even break under the stress of working the slide action. This was changed to the now-familiar dual-action bars in 1970, once Remington’s patent on the dual action-bar design expired.
In 1963, 16- and 20-gauge versions were added to the lineup and a .410 version hit gun shops in 1965.
Other than the addition of a second action bar, the design of the Model 500 remained unchanged for 30 years. But, according to Phil Bourjaily, Shotguns Editor at Field & Stream magazine, the 500 has been the host for a number of first-ever innovations in the shotgun world.
“Mossberg’s 500 looks cheap—it is cheap—but it’s an astonishingly reliable shotgun. Over 9,000,000 have been made since 1961, and they have faithfully served in the field, in squad cars, in the military and beside the bed ever since,” says Bourjaily. “The 500 has also been a platform for innovation. It was the first gun in the industry to offer a cantilever-mount rifled barrel; the first to have interchangeable comb inserts; there was even a .50 caliber inline muzzleloader barrel for the 500.”
A Mossberg for the Military and Police
In the mid-1970s, the company introduced a version of the Model 500 that would expand its reach beyond the civilian and hunting market and into the lucrative police and military market: the M590.
The original 590 came with longer magazine tubes for a higher shell capacity, more robust stocks, and a different magazine tube design. It replaced the Model 500’s closed end with an open end that allows the magazine spring and follower to be removed for easy cleaning. This also saw the jettison of the 500’s fixed locking nut in favor of a ring attached to the barrel that fits around the mag tube, and a removable cap nut that holds the barrel in place, more like the Remington 870. This allows a 590 barrel to be attached to magazine tubes with extensions, something the 500 cannot accommodate.
In the 1980s, the military-specific 590A1 was introduced. It has a trigger guard and safety made of aluminum, instead of a polymer like the 500 and 590. It also has a heavier barrel—a request from the U.S. Navy, so the barrel wouldn’t deform if it were to be accidentally caught in the heavy doors separating tight rooms and corridors onboard Navy vessels.
Mossberg claims the Model 590 is the only shotgun to ever pass the U.S. Army’s Mil-Spec 3443W test, which requires the firing of “3,000 rounds of full-power 12-gauge buckshot.” Updated 3 specs require a metal trigger guard, hence the additional design changes represented in the 590A1.
The Model 590 is available with five- and eight-shot magazines. The 590A1 allows the use of magazine extensions in place of the magazine cap for additional ammo capacity. Long-magazine versions of the 590A1 also include a bayonet lug (though some versions of the 590 do also) and has a more corrosion-resistant coating. It has been adopted by the U.S. Army, Navy, Coast Guard, and several Special Forces units. It has also been issued by several hundred police departments in the U.S., as well as state and federal agencies.
Current Production Model 500s
Today, Mossberg makes the 500 in two broad categories: field models for hunting purposes, and special-purpose models.
Field models are available in a variety of barrel lengths and finishes (including modern camouflage patterns), and with sights or optics. Set-ups include combinations of features optimized for waterfowl, upland game, turkey, and deer hunting. Most smoothbore models come with interchangeable choke tubes and vent-rib barrels, and the receivers are drilled and tapped to accept a rail or scope mounts.
Mossberg also offers a number of combination packages, such as a waterfowl set-up along with an additional rifled barrel for use with slugs, if you want to hunt larger game.
Special Purpose models are intended for self-defense, law enforcement, or military applications. These include the Model 590 and all eight-shot Model 500s. Shotguns in this category typically have short barrels of either 18.5 inches for six-shot models, or 20 inches for eight- and nine-shot models, and synthetic stocks with non-glare matte blue or parkerized finishes.
Some are equipped with special stocks, like the company’s “Speedfeed” stock that hold four additional shells in spring loaded compartments on either side of the buttstock. The newer ATI Tactical version of the Model 500 includes a custom buttstock, pistol grip, forend, Halo heat shield with rail sections, and shell carrier all from ATI Tactical.
These models also sport some of the more tactical features, like ported barrels, muzzle brakes, ghost ring sights, and AR-style buttstocks.
There are also M500s that go the other way when it comes to size and capacity. The 590A1 Compact Cruiser packs the punch and reliability of the M500 in what Mossberg calls a sub-compact pump-action firearm. It has a 10.25-inch heavy-walled barrel with a short 3-round mag tube, a metal trigger guard and safety, and a parkerized finish.
The 500 Compact Cruiser is even smaller, with a 7.5-inch heavy-walled barrel and a 2-round mag tube.
Both guns are too short to use a traditional slide to work the action. Instead, they have an extendable grip that can be used as a vertical foregrip or, when folded, as horizontal slide lever with the assistance of webbing strap. Both shotguns are classified as Any Other Weapon by the ATF, and require a $5 tax stamp and the required NFA transfer paperwork, if local laws allow ownership.
Just this year, at SHOT Show 2017, Mossberg introduced a new version of the M590 that falls somewhere between the Cruiser models and the fuller sized models. The 590 Shockwave is a 12 gauge 590 with a 14-inch barrel, five-round magazine tube, and the Raptor Bird’s Head grip with no stock that is shaped more like the improvised sawed-off shotgun stocks of old rather than a more vertical pistol grip. The shape helps mitigate felt recoil from being directed right into the palm of the shooting hand.
It also has the advantage of being classified as a firearm by the ATF, and therefore requires no extra paperwork or a tax stamp, though its barrel length may still make it illegal in some states.
Over the years, there have been a slew of aftermarket parts designed to expand the capabilities of this basic pump gun, or even just dress it up a little. Mossberg itself once offered a line launcher kit for the 500, which used a special blank cartridge to propel a shaft with an optional floating head and a light rope attached to it. A canister was mounted below the barrel that held the line spool.
Aside from barrels, stocks, forends, on-board ammo carriers, heat shields, and other add-ons in various shapes and sizes—there have even been kits made by third-party vendors that convert the 500 to a bullpup configuration by completely housing the action in the buttstock.
Other products convert the tube magazine into a detachable box magazine setup, like this kit I installed a few years ago on a 12 gauge Mossberg 500, giving the 18-inch barrel shotgun a capacity of 10-rounds in a detachable rotary drum mag, or five rounds in a detachable box magazine.
Those kits are still made today, and the look a little better than the one I used. The modern Sidewinder kits include a rail section for mounting optics and the company also makes staggered higher-capacity box magazines, which are easier to carry than bulky drum mags.
Changes and New Models The 21st Century
In 1988, Mossberg introduced the 835 Ulti-Mag shotgun to appeal to hunters who wanted to use the big new magnum shotgun shells. While it wasn’t exactly a Model 500, the two guns are almost operationally identical. The frame and receiver on the 12 gauge 835 are larger, because it was originally a 10-gauge shotgun. The barrel was then overbored so it could handle 3 ½-inch shells and the muzzle was ported to help deal with the heavy recoil. Because of the overbored barrel, the 835 can’t handle slugs, and parts are not interchangeable with the Model 500.
In 2005, the company brought the M500 platform into the 3 1/2-inch world with the introduction of the Model 535, which is nearly identical to the Model 500, but with a lengthened receiver that can cycle 3 1/2-inch magnum shells, increasingly popular among waterfowlers and turkey hunters. The shotgun can also use 2 ¾- and 3-inch shells. Since the barrel isn’t overbored, it can also handle slug load.
Mossberg makes dedicated rifled slug barrels for the 535, lending it the same versatility as the Model 500. Though they are nearly identical, Model 535 barrels cannot be readily exchanged with Model 500 barrels, because the models have different magazine tube lengths. However, a Model 535 barrel could be put on a Model 500 receiver if the magazine tube is transferred as well.
In 2005 the company also introduced the Model 505, which is scaled down even further from the Bantam and Super Bantam versions of the Model 500. The 505 is available in 20 gauge or .410 bore.
The M500 has also spawned an entire other line of shotguns. In the 1980s, Mossberg introduced the Maverick 88, a line of pump guns that was a budget version of the already affordable M500. The guns are virtually identical in appearance, though factory Maverick 88s are only offered with black, synthetic stocks and forearms with a cylinder bore, and cross-bolt safety. Interchangeable choke systems are offered on hunting models.
Some parts of the Maverick 88 are manufactured outside the U.S., helping cut costs. Though most aftermarket M500 parts can be used on the 88, the trigger groups are not interchangeable—but the barrels, stocks, and magazine tubes can all be swapped (providing the barrels and mag tubes are of accommodating lengths).
The biggest visual difference is the Maverick 88 has its cross-bolt safety mounted on the trigger guard, more like a Remington 870, instead of the top-tang safety of the M500 series. The 88 comes in steel bluing only and the receivers aren’t drilled and tapped for a rail.
The Maverick 88 is offered today in seven different models, including two slug gun versions. Mossberg has continued to upgrade and offer add-ons for the Model 500 with often surprising ingenuity, like the Flex line that makes it even easier to change not just stock and barrels, but forends and grips as well.
But through all the years and innovations, Mossberg has not changed what matters most on these guns: a receiver and action that have been proven to be as rugged as the people who use a Model 500 day in and day out.