Mossberg 590A1

[Slater]

As far as I'm aware, Mossberg is the only shotgun manufacturer that produces a tactical shotgun with a heavy-walled barrel (the 590A1). I read somewhere that the heavy barrel stemmed from some sort of Navy request. Any truth to that or just Interweb BS?

[ryanm]

I believe that is accurate, the barrel shrouds/heat guards will not mount to the 590A1s because of the thicker barrels. Not sure if it was a Navy requirement as much as it was a general durability issue. It is definitely thicker as compared to my 500s. The internals are beefed up as well.

They are a very nice pump shotgun.

[m24shooter]

After the 590 came out the Navy/Marine Corps requested the heavy wall barrel to counter it getting dinged up in an all steel environment as onboard a ship.
The metal safety and trigger guard were also requests. The three upgrades were incorporated into the 590A1, and are the only differences between the 590 and the 590A1 except that the factory A1 receivers are stamped "M590A1."
The internals are exactly the same between the 590 and the 590A1; they are not beefed up. Even the 500 has the same internal components as the 590 and 590A1. The exceptions are the finish.
There were some 500 .mil contract guns that had heavy walls and mag tube cleanouts like the 590 series, and I believe there was even a limited run of heatshields for the A1 from OFM. However, the only place currently producing an A1 heatshield is their LE/.mil service center in Colorado, Aimpro.
DMR has the total picture on the Mossberg production and variants, so maybe he'll post here.

[THCDDM4]

Yeah the H-Bar was added due to Govt./Mil requirements. The 590 A1 is a fine tool, I love mine.

[THCDDM4]

If you bend and play with the 590 heatshield you can get it to fit properly on the A1 (Not my first choice; but for those who bought one on accident, you can modify it to fit.). I know a few guys who did this when they accidentally bought the heat shields for 590's instead of A1's. They took plenty of time bending and reshaping and I couldn't see any MAJOR differences betweeh theirs and my 590 A1 heat shield. FYI.

[ryanm]

I thought the FCG was also changed? I knew it had the metal safety and trigger guard but thought the rest of the small parts were also supposedly improved.

[THCDDM4]

I thought the FCG was also changed? I knew it had the metal safety and trigger guard but thought the rest of the small parts were also supposedly improved.

FCG is the exact same. The H-Bar, Metal Safety and trigger gaurd are the only differences. I've wanted to see a steel receiver in the 590 line up for quite some time now. Not that the aluminum isn't strong as all hell (And I have yet to hear one problem stemming from the aluminum receiver); I just prefer steel...

[DMR]

There are several variants of the Mossberg shotgun in the field. They were type classiffied in the late 70's and have been purchased under multiple contracting vehicles as well as being localy modified in the field.

The base M-500 is a matte blued version of the Mossberg SKU: 50411-9 –– Synthetic; includes Pistol Grip kit –– 18.5" –– Bead –– CYL –– 6 –– 12 –– Blue

You can also find with in the USMC and Navy a version of the 590A1 SKU: 51411-8 –– Synthetic –– 18.5" –– Bead –– CYL –– 6. The Navy/USMC guns can be found listed has having 17" or 20" barrels, but being an Army guy the civilian equal is the 51411-8.

Both the Army and USMC SKU's would be classified under the MIL Spec as being Type II shotguns. The 20" 590A1 shotgun's everyone believes to be "the" military shotguns are Type I shotguns, "with heat sheilds and baynet lugs". The MilSpec also calls for a Rifle sighted "Type III" version, but I have not been able to find an reliable list of them having been procured in large numbers.

There are somewhere between 23,000-30,000 Mossbergs in service depending on your source. FMS sales cut out of the contracts make it hard to determine the exact count without access to LIW or TACOM records. Of those appoximately 95% or more are of "Type 2" configuration. About 1,000 20 "Type 1" configured shotguns were in service off of a one time buy several years ago.

Recently a large command "over hauled" for lack of a better term 1,302 of their Mossberg shotguns. During the process they converted an odd assortment of everything from standard 500's, 20" 590A1's and even some plain 20" 500's into 14" Compacts with several other modifications. The base FCG was retained. These would properly be classified as "Type II" shotguns also.


As for your original question I believe the actual requirement document requesting the change to the heavy barrel walls and metal FCG are lost in the dusts of time. The Mossberg shotgun does not have a PM which manages it or it's requirements. Therefore tracing the source would be difficult, but that is the generaly accepted basis of were the heavy barrel wall on metal trigger group came from. Banging things against bulk heads and all those other objects inside a ship can be hell on any piece of equipment.

My old unit has been banging 500's around since 2001 with no major issues. The configurations remain an issue, but hopefuly we will be able to fix that soon. Training, that's another story

[THCDDM4]

There are several variants of the Mossberg shotgun in the field. They were type classiffied in the late 70's and have been purchased under multiple contracting vehicles as well as being localy modified in the field.

The base M-500 is a matte blued version of the Mossberg SKU: 50411-9 –– Synthetic; includes Pistol Grip kit –– 18.5" –– Bead –– CYL –– 6 –– 12 –– Blue

You can also find with in the USMC and Navy a version of the 590A1 SKU: 51411-8 –– Synthetic –– 18.5" –– Bead –– CYL –– 6. The Navy/USMC guns can be found listed has having 17" or 20" barrels, but being an Army guy the civilian equal is the 51411-8.

Both the Army and USMC SKU's would be classified under the MIL Spec as being Type II shotguns. The 20" 590A1 shotgun's everyone believes to be "the" military shotguns are Type I shotguns, "with heat sheilds and baynet lugs". The MilSpec also calls for a Rifle sighted "Type III" version, but I have not been able to find an reliable list of them having been procured in large numbers.

There are somewhere between 23,000-30,000 Mossbergs in service depending on your source. FMS sales cut out of the contracts make it hard to determine the exact count without access to LIW or TACOM records. Of those appoximately 95% or more are of "Type 2" configuration. About 1,000 20 "Type 1" configured shotguns were in service off of a one time buy several years ago.

Recently a large command "over hauled" for lack of a better term 1,302 of their Mossberg shotguns. During the process they converted an odd assortment of everything from standard 500's, 20" 590A1's and even some plain 20" 500's into 14" Compacts with several other modifications. The base FCG was retained. These would properly be classified as "Type II" shotguns also.


As for your original question I believe the actual requirement document requesting the change to the heavy barrel walls and metal FCG are lost in the dusts of time. The Mossberg shotgun does not have a PM which manages it or it's requirements. Therefore tracing the source would be difficult, but that is the generaly accepted basis of were the heavy barrel wall on metal trigger group came from. Banging things against bulk heads and all those other objects inside a ship can be hell on any piece of equipment.

My old unit has been banging 500's around since 2001 with no major issues. The configurations remain an issue, but hopefuly we will be able to fix that soon. Training, that's another story

Thanks for the run-down DMR; do you think there is a chance we will ever see a steel receiver on the 590 in the future? Just curious.

Where can I get that rail/foregrip/pump in the picture? That looks SWEET!!!!!!!!!

[m24shooter]

Thanks for posting here Rob, I knew you could give way more detail.
I hope that standardization does get done soon.