Mossberg 500


Mossberg 500 is a series of pump action shotguns manufactured by O.F. Mossberg & Sons. The 500 series comprises widely varying models of hammerless repeaters, all of which share the same basic receiver and action, but differ in bore size, barrel length, choke options, magazine capacity, stock and forearm materials. Model numbers included in the 500 series are the 500, 505, 510, 535, and 590.

Basic features

Introduced in 1960, all model 500s are based on the same basic concept designed by Carl Benson. Originally using a single action bar that was known to bind and even break, this was changed to dual action bars in 1970, following the expiration of Remington's patent on the double action bar design. A single large locking lug is used to secure the breech. The magazine tube is located below the barrel, and is screwed into the receiver. The slide release is located to the left rear of the trigger guard, and the safety is located on the upper rear of the receiver.
Sights vary from model to model, from a simple bead sight to a receiver-mounted ghost ring or an integrated base for a telescopic sight. Most models come with the receiver drilled and tapped for the installation of a rear sight or a scope base. The factory scope base is attached to the barrel via a cantilever-type mount, which places the scope over the receiver but keeps it with the barrel if the barrel is removed.
Intended for use in harsh and dirty conditions, such as waterfowl hunting or combat, the Model 500 series is designed to be easy to clean and maintain. All Model 500s feature interchangeable barrels, which may be removed without the use of tools, by loosening a screw on the end of the magazine tube, allowing the barrel to be removed.
Dual action bars connect the fore-end to the bolt, and generous clearances between the steel action bars and their receiver channels reduce wear on the aluminium receiver while allowing the shotgun to function with the presence of dirt or debris. The Model 500's bolt locks into a recess located on the top of the steel barrel instead of the receiver itself, thus allowing the use of lightweight aluminum instead of steel. The trigger housing and safety button are made of plastic to reduce cost.

Disassembly

The trigger assembly, which includes the trigger, hammer, sear, and trigger body with guard, can be removed by pushing out one retaining pin and pulling downwards on the guard. The elevator can be removed by putting the gun on safety and squeezing the sides together, freeing the pivot pins from the receiver. The fore-end can then be moved to the rear, allowing the bolt and bolt carrier to drop out, and then the forend can be removed by moving it forward. The cartridge stop and interrupter will then fall free, leaving just the ejector and the safety in the receiver, held in by screws. The magazine spring and follower may be removed by unscrewing the tube from the receiver. This level of field stripping is sufficient to allow all components to be cleaned.

Model 500 options

The name "Model 500" covers an entire family of pump shotguns designed to chamber "magnum" shells. The standard model holds five or five shells in the magazine and one in the chamber. The Model 500 is available in 12 gauge, 20 gauge, and.410 bore, with the 12 gauge being the most popular and having the most optional features available. A 16 gauge was offered at one time but has been discontinued.

Finishes

The standard finish for the Model 500 is an anodized aluminum alloy receiver and a polished and blued barrel. Some models come with a matte black matte-anodized receiver, and a matte blued barrel. Some 500 models are anodized to look parkerized, with parkerized barrels. This is also true of the 590 series since an aluminum receiver cannot be parkerized.
Mossberg also offers camouflage painted models, in a number of different patterns. Stocks are either wood or composite, with the composite stocks being matte black or camouflage to match the rest of the gun. A special model called the Mariner is available with the Marinecote finish, an electroless-nickel finish that is highly corrosion resistant. Mariner models use the black composite stocks.

Model 500 vs. Model 590 vs. Model 590A1

The primary difference between the Model 500 and Model 590 is in magazine tube design. The Model 500 magazines are closed at the muzzle end, and the barrel is held in place by bolting into a threaded hole at the end of the magazine tube. Model 590 magazines are designed to be opened at the muzzle end, and the barrels fit around the magazine tube and are held on by a capnut at the end. The Model 500 magazine facilitates easy barrel changes, as the barrel bolt serves no function other than holding the barrel in place. The Model 590 magazine facilitates easy cleaning and parts replacement, as removing the nut allows removal of the magazine spring and follower.
Both the Model 500 and Model 590 have polymer trigger guards and safeties, and standard barrels. The Model 590A1 has an aluminum trigger guard and safety, a heavier barrel, and a bayonet lug, intended for military use under extreme conditions and rough handling; the metal trigger guard was added in response to the 3443G materials requirements, and the heavy barrel was added at the request of the Navy to prevent barrel deformation if the shotgun caught in the closing of heavy steel ship doors. Some 590A1s have a sling swivel on the back of the bayonet lug, some do not. The 590A1 usually has a swivel mount on the stock even when there is no corresponding mount on the forward end of the weapon. The 590A1 is generally sold through military and law enforcement channels, though in most jurisdictions the and barreled models are available and may be legally purchased by any non-prohibited persons. 590A1s with 14" barrels are Title II firearms, and may be purchased only by non-prohibited persons in NFA-legal states, after completing BATF transfer forms.
The riot gun versions of the pistol grip Model 500 are available with an and barrel depending on magazine capacity. The 590 is only available with a barrel and flush-fit magazine tube. The 590A1 is available with a, 18.5-inch, or barrel. One model sold as Model 590-SP is technically a 590A1, as it uses the heavy barrel and military trigger group, but unlike models designated 590A1 it is sold on the civilian market.
Unlike Model 500 and 590 shotguns, Model 590A1 shotguns cannot be easily fitted with the common factory 500 heat shield, due to the heavier barrel. A heat shield and bayonet lug are required for military 3443G Type I riot shotguns, and some 590A1s are so equipped. The 590A1 heat shield, p/n 16335P, is available for purchase from Mossberg for about the same price as the 500 heat shield.

Bantam and Super Bantam models

The standard Model 500 uses a length of pull for the stock, which is suitable for adult shooters of average or greater size. The Bantam models use a LOP stock and a forend that sits further back than the standard model. The Super Bantam stock includes two recoil pads and a stock spacer.
By using the short pad, the LOP can be reduced to ; with the spacer and longer pad, the LOP is. A number of different models are offered with Bantam and Super Bantam stocks, or they can be ordered as accessories and fitted to any Model 500.

Model 505

The new Model 505 Youth shotgun, introduced in 2005, is similar to the Bantam but scaled down further. The 505 has a LOP buttstock, a barrel, and a four-shot magazine tube. The 505 is available in 20 gauge and.410 bore. Parts are not interchangeable with other model 500 variants.

Model 535

The Model 535, new for 2005, is similar to the Model 500, but with a lengthened receiver that can fire shells, in addition to and shells. The 535 is a less expensive alternative to the Mossberg 835 Ulti-Mag, but the 535 lacks the 835's overbored barrel. The non-overbored barrel of the 535 does, however, allow the use of slugs, which cannot be used in the overbored barrel of the 835.
Model 535 barrels are not interchangeable with Model 500 or Model 835 barrels, but 535 barrels are available in smoothbore and rifled in a variety of vent ribbed, barrel lengths and different sights. The 535 is also available in a tactical model with ghost ring sights and a collapsible pistol grip buttstock. Although Model 500 barrels can be used with Model 535 receivers, magazine tubes from the Model 500 must also be used because of the magazine tube length difference.

Magazine capacity

The Model 500 comes in a variety of different receiver configurations, whose main difference is the magazine configuration. The basic Model 500 comes with a magazine tube capable of holding five shells, which is called a six-shot model. The 500 is also available with an extended magazine tube that holds seven rounds, making an eight-shot model. The 590A1 is available with five- and eight-shot magazines, sold as six- and nine-shot models respectively. The Model 590A1 also allows the use of magazine extensions in place of the magazine cap to further increase the capacity of ammunition.
The variants with the extended magazine tubes use different barrels, as the barrel is held in place by attaching at the end of the magazine tube. The shortest barrel length available for the eight- and nine-shot models is, which fits flush with the long magazine tube. A ribbed modified choke field barrel was also manufactured for the 8-shot model 500. The shortest barrel for Title I six-shot models is, while military and law enforcement personnel can also get a barrel, which uses a special 5-shot magazine.

Model 500 variants

The Model 500 is available in many variants, for a wide variety of applications. The ease of changing barrels on the Model 500 means that a single shotgun may be equipped by the owner with a number of barrels, each for a different purpose. As sold, the Model 500 is generally classed into two broad categories: field models and special purpose models.

Field models

Field models are the basic sporting models. They are available with a variety of barrel lengths and finishes, and may be set up for waterfowl hunting, upland game hunting, turkey hunting, or shooting slugs. Most smoothbore models come with interchangeable choke tubes and vent rib barrels, while the slug models come with rifle sights or scope bases, and may have smooth cylinder bore or rifled barrels.

Special purpose models

Special purpose models are intended for self defense, police, or military use. The Model 590 and the eight-shot Model 500s are only sold as special purpose models. Special purpose models have short barrels, either for the six-shot models, or for the eight- and nine-shot models, but the barrels are fully interchangeable with all models of the same magazine tube length and in the 500 family. Most models come with special designations like SPX, Tactical, Mariner, etc.
Special purpose models may be equipped with a variety of specialty parts which may include adjustable stock, "Speedfeed" stock that holds four additional rounds of ammunition, pistol grip, ghost ring and fiber optic sights, Picatinny rail, forearm band, heatshield, ported barrel, muzzle brake, and even a bayonet lug. All special purpose models come only in black trim with either blued, non-glare matte blue, or parkerized finishes and now come with drilled and tapped receivers for scope and optics mounting.
"Special Purpose" models are not the same as "Law Enforcement" models; the latter have heavier duty barrels, safeties, trigger guards, and will stand up to harder use.
In 2018, Mossberg released the 590M, a pump-action shotgun fed by a double-stack magazine. It is available in three models; one is a derivative of the Shockwave, the other two are variants of the base 590, one having ghost ring sights and a heat shield, the other without. The magazines are available in 5, 10, 15, and 20-round capacities.

Law enforcement models

Mossberg shotguns currently designated "law enforcement models" are 590A1s. 590A1s differ from other 500/590 shotguns, in that they have heavy barrels, metal trigger guards, and metal safeties. 590A1s are available in,, and barrels. The 590A1 is also used by the U.S. and allied armed forces, having been designed to meet the stricter standards outlined by the U.S. Army.
Model 500s were also previously sold as law enforcement combos in 12 gauge with both and barrels, birch buttstock, pistol grip and sling.

Home security model

The model 500 HS410, or "Home Security" model, is available in.410 gauge only, and is specifically designed for defensive use. It comes with a youth-sized stock, a vertical foregrip, and a special muzzle brake and spreader choke on an bead sight barrel. The.410 gauge round, while by far the least powerful common shotgun chambering, remains a formidable shotgun shell. A 90-grain slug generates energy close to a.357 Magnum when fired from a full length barrel. The HS410 is targeted at the novice user who desires a simple, easy to use, and effective defensive weapon. It is packaged with an introductory video covering use and safety, and some versions have a laser sight mounted in the foregrip.

Mossberg Shockwave

The Mossberg Shockwave is a pump action firearm based on the 590 series of shotguns. It is distinguished from the rest of the 590 series by its barrel and "birds-head" style grip.

Design

The action of the Shockwave is taken from Mossberg's 590 series of shotguns. It features the same sliding tang safety on the top rear of the receiver, twin action bars, and dual extractors seen on other models. The name is inherited from the manufacturer of the grip, Shockwave Technologies. Mossberg claims the grip reduces recoil. The Shockwave weighs empty, holds five rounds in the magazine tube, and has a single brass bead front sight with no rear sight. Production began in 2017 with a 12 gauge model, adding 20 gauge and.410 bore models later.

Legality

In the United States, the Shockwave does not fit the definition of a shotgun as defined by the ATF, which says that shotguns have barrels over in length and are made to be fired from the shoulder. It avoids restriction as a short barrel shotgun under Title II of federal firearm laws by remaining over in length and not being made to have a shoulder stock. The ATF refers to the Shockwave as a non-NFA firearm. While legal without a tax stamp at a federal level, regulations also vary by state, thereby prohibiting purchase in some states.

Accessories and combinations

The Mossberg 500 has always been marketed as a multi-purpose firearm. Mossberg sells a wide variety of accessory stocks and barrels, allowing many configurations to be made. Mossberg is also the only company to ever offer a double-action-only model. The model 590DA offers a longer, heavier trigger pull to reduce the chance of an accidental discharge by the operator, and was targeted at the police market.
With the appropriate parts, the same Model 500 can be a field gun, a slug gun, defensive weapon for civilian, police, or military use, trap and skeet gun, or.50 caliber rifled muzzleloader.
Mossberg has also sold "combination" sets, with a single receiver and more than one barrel. Common examples included a field barrel packaged with an cylinder bore barrel for defensive use, or a field barrel and a slug barrel, or a slug barrel and a.50 caliber muzzleloading rifle barrel.
A unique item offered by Mossberg for the Model 500 is a line launcher kit. It uses special blank cartridge to propel a shaft with an optional floating head and a light rope attached to it; a canister hung below the barrel to hold the line spool. A test of the Mossberg 500 with line launcher by the BoatUS Foundation showed an average range of over with the floating head. Distances of are claimed for the non-floating long distance head.
All Mossberg models including the 835, 535, 500, 505 and 590 are shipped with a wooden dowel with two rubber O-rings, also called a duck plug, located in the tube magazine. This is to comply with U.S. migratory bird laws. This dowel reduces and regulates the number of shells that can be loaded in the magazine to 2. This can be removed by taking off the barrel, pointing the shotgun downward, and shaking it back and forth lightly until the dowel shows out of the end of the magazine tube. It must then be pulled out, the O-rings prevent it from just falling out. Except for the Maverick 88, all current production Mossberg models have a pre-drilled receiver for installation of an upper Picatinny rail for mounting various optics such as red dot sights. Some models can be bought with the rail and accessories already installed.

Maverick Arms subsidiary

Mossberg also markets a less expensive shotgun under the Maverick Arms name, the Mossberg Maverick 88, in blued finish with synthetic stocks, and in appearance is virtually identical to the 500 model. Maverick and Mossberg shotguns share many interchangeable parts but Maverick shotguns differ in some ways, such as lacking sling swivel studs and having cross-bolt safeties instead of tang safeties, which makes the trigger group non-interchangeable with the Model 500 shotgun. The one-piece forearm can be replaced with OEM or after market parts with the addition of an action slide tube, as the factory forearm has the action bars pinned into place. The Maverick series also does not come drilled and tapped for rail mounts like the 500 models. There are two basic models of the 88, the 88 field and the 88 security, with a cartridge capacity of six or eight shots, and they cannot have their magazines easily extended without machining. The factory warranty on Maverick shotguns is limited to one year.

Model numbers

Mossberg claims the Model 500 is the only shotgun to pass the U.S. Army's Mil-Spec 3443E test, "a brutal and unforgiving torture test with 3,000 rounds of full power 12 gauge buckshot". The 500M MILS have the metal trigger group, and the heavier 20 in barrel.
While the Marines officially switched to the semi-automatic M1014 Combat Shotgun in 1999, various branches of the U.S. military are still acquiring pump shotguns.
In 2009, U.S. Army Special Forces Groups procured Military Enhancement Kits to provide a standardized shotgun configuration based on the Mossberg 500. The kits included a collapsible stock, "shotgun retention system", 1913 receiver rail, fore end rail system and breaching barrels. A total of 1301 shotguns were converted with the first unit being equipped in July 2009. The majority of the kits convert the standard issue shotgun to a 14" compact model with a 16" accessory breaching barrel, H92239-09-P-0113.
As of 2012, the U.S. Army is in the process of replacing the M500 with the M26 Modular Accessory Shotgun System, of which 9,000 are funded and under contract. The new shotgun is designed to be mounted in an underbarrel configuration on an M4 Carbine, similar to the M203 or M320 grenade launchers, or used as a stand-alone weapon.

Users

Mossberg produced two U.S. military versions of the model 500, the 500 MILS and the 500M MILS, the difference being the location of the upper sling swivel. The model numbers contain a U.S. prefix to the serial number. These particular models contain all metal parts, are parkerized with a 20-inch barrel. The magazine capacity is 6+1.
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