Moss500full.JPG (55815 bytes)



Moss12x12full.JPG (62632 bytes)

of it


A conspiracy of Miles Fortis and A K Church


The Mossberg 500 was introduced in 1962, and was directed at the low end of the slide-action shotgun marketplace. Construction is of many parts designed around simple construction, and useable without fitting. Early guns can be distinguished by a single action bar, and the absence of serial numbers.

The gun has outlived the contemporary competition. The tang mounted safety, excellent ergonomics, and great reliability have kept it going. These guns are now about as common as Ruger 10-22s.

I do believe almost all rural residences eventually acquire a Mossberg by some sort of osmosis.

In the period since, Mossberg has introduced a companion line designated as "Maverick", and as one would expect from a gun commemorating the Ford Falcon's $1995 replacement, this is directed at an even lower price point. Primary difference is moving the excellent tang safety (whose slot requires a small amount of machining) to the polymer trigger group. Most parts are interchangeable with Mossberg 500 pieces. We have tested this with an available Maverick. By interchanging trigger groups it is possible to construct: (1) A Maverick with no safety; (2) A Mossberg with two safeties.



The bolt contains a cammed block which locks into a cut on the barrel extension. The actual lockup appears to be nearly identical to an older Stevens pump gun, save that the Stevens employed an actual cut through the roof of the receiver.

The trigger group itself is modular, and retained by springloaded pins. It is a marvel of efficient use of space, and, like the rest of the gun, it contains nothing in the way of fine milled forgings. Parts are either polymer, sheet steel stampings, or castings. Disassembly is straightforward, reassembly is of Byzantine complexity. Indeed, it may be impossible for one person.

The receiver is a milled aluminum forging, but one suspects it is forged very close to finished dimensions.


The test guns are: (1), A 1979 vintage military trench gun, the model 500-ATP-8SP, essentially an early model 590, and (2), A Cobray "manufactured" Any Other Weapon styled as "The Rogue". The trench gun carries a full buttstock, a lug for M7 bayonet (M16 type), heatshield and 20 inch cylinder barrel.

The Cobray carries a Pachmayr Vindicator pistol grip (thank God for small favors), a 12 inch, heatshielded barrel, a severely foreshortened magazine, slide handle and a world of bad attitude. This would be, if locally legal, the paradigmatic nasty car gun.

The trench gun was purchased new in the fall of 1979. In the period since, it has been shot until the wooden buttstock cracked, the plastic safety button shattered, the magazine follower began to split, and the finish turned crusty. The safety was replaced with an aluminum button crafted by the late Jack Clark (see my Remington 700 article). None of this happened precipitously though, as it has had over 5,000 rounds of full charge 12 gauge run through it.

The Cobray is a 1985 vintage gun, legally assembled as an Any Other Weapon on a Mossberg receiver. The barrel, magazine, action bar handle and action bar are specific to this series.

Miles later added an additional 15" barrel cut to length and finished by his dad so as to get that one extra round available with the standard length magazine. Cobray manufactured these guns for less than 2 years. By Law these are Any Other Weapons by virtue of original "manufacture" with short barrel, but with out buttstock. Legally it is a type of smoothbore pistol.


The 500 trench gun handles approximately the same as any other extended magazine riot gun. The excellent tang safety falls quickly to hand for activation, and is more or less ambidextrous. The action release is located at the rear of the trigger guard, and while presumably designed for right-handers, left-handed Miles finds both a satisfactory arrangement.

Recoil is on a par for a 6.5 pound pump 12 gauge. The buttstock is well shaped, the Choate replacement duplicating the drop and pull of the long gone "walnut stained hardwood". Personal opinion is that you are in no danger of your teeth popping out.

The shorty is another story. The original manufacture pared away more than two pounds. Every ounce not there is felt in firing. The gun is a hard kicker, and recoil goes straight to the web of the hand. 3" magnums require a supported firing hand-usually the hand is braced against the hipbone. Even standard 2 3/4" field loads are unpleasant pretty quickly. It has perhaps 100 rounds run through it.

I admit it. Miles and I have run BRI sabot slugs through it. 

1 round each.


We herewith reproduce patterns fired at 20 yards using Winchester 2.75" #6 field loads, and 00 buck. We attempted to use the 2" Aguila ultrashort round, which proved a tangle of feed problems, as the ammo box itself warned. The Aguila testing was suspended. 

Not a lot to say here. These guns pattern like cylinder bored 12 gauges.( as always, larger images are available if you click on them.)

Moss12x12s00.JPG (155193 bytes) The "12x12" (as A.K named it years ago) Moss12x12s6shot.JPG (154635 bytes)

Moss500s00.JPG (144632 bytes)         The "normal" Mossberg               Moss500s6shot.JPG (168580 bytes)

As you can see, the length of the barrel really doesn't have a lot to do with pattern size.


Make sure the gun is unloaded. Both the chamber and the magazine. This is for field stripping. Detail stripping is more involved, and will not be fully covered here.

(1) Retract the bolt about an inch. This disengages the locking lug from the barrel.

Mossstep1.JPG (132907 bytes)

(2) Unscrew the barrel retaining cap attaching the barrel to the front of the magazine tube.

Mossstep2.JPG (85947 bytes)

(3) Pull the barrel off the gun.

           Mossstep3.JPG (152984 bytes)          Mossstep4.JPG (136321 bytes)       

(4) Field stripping is complete, and reassembly really is in reverse order.

This ease in disassembly has also allowed the type to be one of the more versatile shotguns available. One can simple purchase different barrels and change them for the intended purpose. They are available from 18 1/2 inch length and longer for different hunting and social activities.


Loading port is located in the typical bottom of receiver location. Magazine capacity will vary between 2.75" and 3" rounds, the latter will reduce capacity. The test guns have magazine capacities of 8 and 4 rounds of 2.75" respectively.

Action release is located on the operator's left at rear of trigger guard. Pressing upward will allow the forend to be retracted. Shuck the forend rearward vigorously, pull it back forward, and gun is loaded.

The safety is located at top rear of the receiver. Pushing it forward is the "fire" position, rearward is the "safe".


There are some mildly complex procedures which do not lend themselves to digital photography. For this reason we have not opted to include these instructions. They are laid out in the owner's manual.

The trigger group is beyond mildly complex to reassemble. Mine was replaced after we gave up on reassembly. Theoretically Mossberg restricts the trigger/hammer module to factory replacement only-Gun Parts Corporation, last I was aware, will sell the part to anyone. They sold it to me, anyway.

In general, detail stripping will only be required if the gun has been fired a great deal, or in the unlikely event of required parts replacement. The Mossberg is right tolerant of dirt and filth.

Aerosol solvents and/or cleaners have developed to the point full detail stripping for cleaning is hardly needed.


Beyond 3000 rounds, the buttstock commenced cracking at the pistol grip. Acra-glas failed to halt this, so a Choate synthetic replaced the wood. I suspect it will last well past my life.

After years of loaded storage, the stamped sheet steel magazine follower developed a crack. It continued to work 100% until the Choate fiberglass/polymer unit was installed. It tops the original magazine spring, I will mention.

Eventually, the plastic safety button broke, after many thousands of operations. The late Jack Clark milled a replacement out of aircraft aluminum. Jack's been gone a few years, but the safeties he made for my trench gun (and later Miles' shorty) soldier on.

The trench gun came from the factory with a blued heatshield-although the gun is Parkerized. The heatshield will move forward under recoil, gouging the finish. I considered removing the shield altogether until the alleged President passed legislation declaiming heatshields to be components of Assault Weapons. I then decided the forbidden allure of these evil guns was too overpowering, so the heatshield remains.

Both Miles and I are well and truly taken with our Mossbergs. They have lasted well, are reliable, and we trust them.

Email  Miles or; A K Church may be chastised, or sent sent clever palindromes


Hit Counter