> TEOTWAWKI Blog: Project 590A1: Intro



Project 590A1: Intro

A few weeks back, I picked up a Mossberg 590A1, with some uncertain plans for performing some upgrades to the shotgun. Taking a cue from TSLRF's Project 870 (Thanks Ryan!), I thought I would let the T-Blog Tribe follow along as I went through the upgrades--and some trial/error--to the 590A1.

The 590A1 is, of course, an already upgraded version of the popular Mossberg 500. The 590A1 is the heavy-duty, milspec version of the 500, with all metal parts, a thicker barrel and a different magazine tube--the mag tube opens at the end, facilitating cleaning. Parts between the 590A1 and other 500 series shotguns are largely interchangeable; if you've got a 500 or 590 (or Maverick--I'm pretty sure those are patterned after the 500), you'll be able to follow along, too.

The 590A1 is probably needlessly heavy duty for most uses--the thick walled barrel especially--and is noticeably heavier than a standard 500. But, for rough use and dependability, the hard-use components are a good thing--the 590A1 was designed for military use and has served successfully with various branches of the military. For apocalyptic mutant zombie biker slaying, why the heck not go with the toughest thing out there?

Why a shotgun at all? Well, I'm a rifle dude first and foremost, but, let's face it, every arsenal needs a 12 gauge pump. Mine was lacking one, so I figured I might as well fill that hole in style. 12 gauge is super versatile, super common (as in you can still find it in stock!) and devastatingly effective in combat with the right loads. And, it was a weapon system that I was not particularly familiar with, and I was up or gaining some skills on a new platform.

Why choose the 590A1 over another design? To me, the Mossberg 500 series and Remington's 870 are largely interchangeable in terms of quality and ruggedness. I like the location of the Mossberg's controls a bit better, I like the look better, and, they tend to be easier to find in full-on combat configuration. Yes, I wanted a bayonet lug, 'cuz every end of the world shotgun needs to have that capability. So Mossberg it was.

My 590A1 is a 20" model--a bit long, but it also bestows the wielder with a full 8+1 shell capacity. Nine rounds of double aught buck is nothing to sneeze at.

Clearly, this ain't a duck gun. I shot some skeet with it on its first outing, and, well, the short-ish barrel and cylinder bore aren't the best combo for knocking clays out of the sky.

Naa, this is an evil-slaying black shotgun, amigos. And, over the course of this series, we're going to crank up is evil-slaying capabilities a couple notches.

Home defense? Of course. Go-to for ban states? Yep. Last stand against the undead? That too.

Ya, we're going to have a bit of fun with this one. Stay tuned for more.


  1. Great start (putting on the Jiffy Pop on stove) lets see where this one ends up. Sure to be plenty of discussion - the pump 12 is one of the Holy Three to defend your life.

  2. Definitely going to be one of my next firearm purchases. Like yourself I feel as though the Mossbergs and the Remingtons are nearly interchangeable. I want to get a compact for my wife, a compact for myself for an EDC, and then I will be purchasing a shotgun. After that its all "fun and games" as far as what my firearm purchases will be. A 1911 and an AR15 are in there somewhere down the line.

  3. Great project! I went with a Mossberg 500 for my Home Defense Shotty. I found a cheapo and resurrected it.


  4. Thanks for the linkeage. I think you definitely need a bayonet. Preferably a ridiculously long one. Not much says I am not playing like a pump 12 gauge with a huge bayonet on the end.

    1. I'm hoping to find something that more of a short sword than a simple bayonet, but we'll see.

  5. All the current stink in Washington these days, but I can tell y'all one thing: An idiot with Dad's AR may hurt people.
    Few in liberal gun-grabbing politics know what 00 Buck does upon what its fired at.
    8 rounds out of a Garand....10 out of a semi auto AR or AK.
    None surpass the good ole 12 guage pump, regardless who made it. At decent range its the most devasting weopen invented.
    Thankfully these politicians are so ignorant to try to limit me to 8 shots, when 2 do more than the job.

  6. Just got one of these myself, so I am looking forward to the mod. Still awaiting Magpul to come out with the similar fittings it has for the Rem 870. However, with their moving from Colorado there might be a delay.


    Remington's 870 and Mossberg's 500/590/Maverick are interchangeable only in their applied use. But if you look at the user buttons and reliability, there are a few important differences.
    Most importantly, the loading system is fundamentally superior in the 500 variants. While the pump forend is forward, you will notice that the cavity on the bottom is open. If a round is released due to jarring-the round will simply fall out.... No jam!
    However, if the same thing happens with the 870, you get a catastrophic jam that is tedious to clear. This is sure to the loading arm being in the DOWN position. This is the very reason why the US military rejected the 870.
    Good choice with the Mossberg.
    On a side note, the Maverick is identical to the 500 except the furniture is more economical. Think Sears version of the 94 lever action.
    Also, the Maverick features a safety that is located near the trigger..... So, special forces that utilize a top folding stock will start with the Maverick instead of the 500.
    I grew up with an 870 in my hands, but I must admit that the 500 provides a more reliable combat platform.

  8. In defense of the 870....

    I'd start by saying that this is another fantastic thread on a fun web-site! I think the 590A1 is a great shotgun for general defensive use, as a patrol gun, and as a TEOTWAWKI firearm.

    All of that said, not everyone prefers to have the safety on the top of the stock/receiver. In fact I think the 870's operating system is better for tactical use. It could be personal preference but I don't seem to have to move my hand as much when operating the manual of arms with the 870 as when I've qualified with the Mossbergs. I like the better finish and the all steel receiver of the 870. For me at least, it is just as easy to tell if the gun is "on safe" or "hot". Additionally,the 870 has always had two slide bars (I think Mossbergs now do too though..)and I've always found the spring loaded load gate is a better, more reliable design than the open system on the Mossbergs. I actually think it is less likely to have a shell pop out of the tube because of that cover/gate.

    My understanding was that the lower cost of the Mossberg (because of the aluminium receiver?)was the primary reason that drove the military's selection of the Mossberg. Perhaps the lighter weight because of the aluminum receiver is another reason. Note, the 870 is still widely used in the US Military Police and Special operations teams of all branches. Some teams/operators select them when they have the unit budget to buy their own.

    The only 12 GA I own is a vanilla 870 Express with an 18.5" barrel. Mine has the 4 round magazine tube only because I wanted to be able to switch out to a hunting barrel without dealing with the extender. In retrospect I kind of wish I'd bought the 7 round tube model (I suppose I can still modify it).

    Personal preferences aside these are both excellent designs that have served with distinction.

    Thanks again for a great, informative web-blog!


    1. Colorado -

      The 870's controls, I think, are also more suited towards running a pistol grip style stock. And procedures for performing a slug changeover are better on the 870 as well.

      Both have been in service in the hands of armed professionals of all sorts, so it's pretty much as wash there. And if I remember right, the pump guns are being phase out in favor of semi auto Bennelis.

      Anyways, quality designs with their associated tradeoffs--can't really go wrong with either!

    2. Here's how I view the choice between an 870 or a 590. Toe the two are very comparable in quality and have both proven themselves in military and civilian combat. But fore it all comes down to two things: the location of the safety and more importantly the location of the slide release. If you are running a pistol grip stock, the mossberg controls are not convenient to use. If you are running a traditional stock they are more convenient IMHO.. I have a Benelli Nova Tactical as my defense shotgun currently. But I want to add a Mossy 590A1 soon. But I will not be putting a stock with a pistol grip on it.

  9. Put a Sidesaddle shell holder on it and add a sling and then your done. Enough said. If you want to get fancy maybe install a Speed Feed Stock.

  10. Joe Biden gave me the OK to pick up a Mossy 500 recently so I will be looking forward to seeing what ya got coming.

    1. That's just a simple political distraction from their real objective. The Obama bin Biden regime isn't going to stop until ALL guns are banned. If ya think the gun control pressure is bad now, wait til the possible election of Ole Hilary Clinton in 2016!

  11. Really looking forward to this series. I have a 590 & a 590A1 and have been in the process of doing the same thing on both of them. I recently added a Mesa Tactical 6 round side saddle, GG&G sling attachment, and tritium bead front night sight and am wondering what else to do.

    I am trying to find the best option for a tactical flashlight and mount but haven't been successful yet.

    I am also looking at a 8 MOA red dot like the Burris Fast Fire 2 but haven't made a final decisions yet so again, I am really looking forward to this series.

  12. +1 on the Mossbergs. A 590A1 has been on my list for a while.

    I'm running a synthetic stocked 870 right now. I think that Remington has some quality control issues these days. Mine basically sat in the safe for the first year I owned it, and there were rust spots on the receiver when I took it out.

    Apart from that, the cross-bolt safety isn't so convenient. The receiver isn't tapped. I don't so much mind the location of the slide release, but the tang safety on the Mossy beats the cross-bolt all to hell.