Bringing a 590 up to 590A1 (Mil-Spec 3443) standards...

[Moose-Knuckle]

Back story:

I am suffering from a little buyer’s remorse as I made an uneducated decision when I was 19 years old (11 years ago) and bought my first firearm. The Clinton Crime Bill was still in effect and I was not old enough to legally purchase a handgun so I decided to go with a pump-action 12 gauge shotgun. In my research and limited access to subject matter knowledge I chose to go with a Mossberg 590 Special Purpose as I “heard” and read in gun rags that it was “Mil-Spec”. Back then I went to my local Wal-Mart and asked the clerk behind the hunting counter for the special order catalog and placed my order for the 590.

Fast forward to today I still have said Mossberg 590 but have since learned that it is not a 590A1. To my knowledge the differences are:

• 590 has a trigger assembly with a plastic trigger guard, aluminum on the 590A1.

• 590 has a plastic safety button, aluminum on the 590A1.

• 590 has a standard 20” barrel, heavy walled barrel (which negates the installation of a heat shield) on the 590A1.

So to upgrade my 590 I will need to replace above mentioned parts with OEM trigger assembly with aluminum trigger guard, aluminum safety button, and a heavy walled barrel (with rifle sights while I’m at it). I will also be replacing the magazine spring with a Wolff and possibly a high visibility follower.

Are there any other parts and or modifications that I am leaving out?

[whiterabbit05]

Don't bother, just shoot it and be happy.

You've already had it for 11 years without the need for a metal trigger guard, safety, and heat shield, what makes you think you need it now?

[austinN4]

Don't bother, just shoot it and be happy.

I agree. I used to collect HD shotguns (hence the screen name) and had a 20" 590A1, model 51663. While I prefer the controls on the Mossberg it was too heavy and too long for a house gun.

What I really lust after is the 14" 590A1, perfect for a house gun IMO.
http://www.impactguns.com/store/015813526890.html

Edited to add: The only thing I would change on your 590 is the safety control. I would replace it with a metal one. The plastic trigger guard doesn't bother me in the least.

[Moose-Knuckle]

Don't bother, just shoot it and be happy.

You've already had it for 11 years without the need for a metal trigger guard, safety, and heat shield, what makes you think you need it now?

Well for starters it's not what I thought it was when I purchased it. My 590 has the heat shield from the factory. I wanted a "mil-spec" pump shotgun, cliché maybe but if I had it to do over again I would have opted for the 590A1 or an 870P. At that time I didn't even know there was an A1 or what the differances were from an 870 Express and an 870P. "Knowing is half the battle"...

[Moose-Knuckle]

I agree. I used to collect HD shotguns (hence the screen name) and had a 20" 590A1, model 51663. While I prefer the controls on the Mossberg it was too heavy and too long for a house gun.

What I really lust after is the 14" 590A1, perfect for a house gun IMO.
http://www.impactguns.com/store/015813526890.html

I agree on the length. I always felt the 20" barrel was cumbersome for a house gun. There was a time when I wanted a Winchester Defender just to have the 18" barrel.

[austinN4]

There was a time when I wanted a Winchester Defender just to have the 18" barrel.

Had an 18" 1300 Defender, too - it kicked like a mule.

[MAX100]

It would be too costly. Just sell yours and buy an A1 if that's what you want.

I would add an aluminum safety and leave the rest the way it is.

GC

[CGSteve]

If it is mainly for the collection to have a mil issue shotgun, I believe the 590 has been issued in addition to the A1 variant. My convoy security team was issued plain old Mossberg 500A shotguns along with one Benelli M4.

I had the same gripe I think you're having as well and figured it wasn't worth it. I have not looked recently but the sight upgrade is also nowhere to be found.

[Moose-Knuckle]

I have not looked recently but the sight upgrade is also nowhere to be found.

Brownells sells the OEM 20" barrel with rifle sights.

[DMR]

Moose-Knuckle,

I'd say just stay with what you have for many reasons. Per the MIL-SPEC your current shotgun would be a TYPE I, which requires a heat shield. The primary procurements have all been for Type II shotguns. VERY Few Type III shotguns, which call for rilfe/ghost ring sights, were ever procured, i.e. fewer then the Type I's.

The most common issue shotguns are Type II's which are actualy a plain old 18" Mossberg 500 (P/N 50411-9) in the Army. The second most common Type II's are a 17" or 18" Mossberg 590A1 (P/N 51411-8) for the Navy and Marines. Only about 1,000 Type I Mossberg 590's in the 20" heat sheild version were ever purchased. Many of those went to the Special Forces and various other units. of those issued to SF, most have recently been converted to 14" Compacts, with spare 16" breaching barrels, and would be classified as Type II's.

Example of a Type II varent using a 500 reciever, but the USMC/Navy barrel and mag tube system.


For the Army issue 500's they use the plastic trigger guard. In the 9 years we have been using them here, I am unaware of breakage being an issue. The Army relpaces the whole trigger group if they are broken because they by the trigger housing for less then the man hours to take one apart.

The 20" A1 is a great beast of a shotgun, but for a 20" gun I would prefer the better handling of the plain 590.

Look for a comparision from stickman in the future