The standard issue pump action shotgun of the United States military is the Mossberg 590A1. Mostly, there are still some Mossberg 590s and 500 MILS still kicking around. Shotguns are a fairly niche weapon for the military, so they tend to fall into crevices and be forgotten about. Heck, there is a 590A2 now, which is a modified 590A1, and it’s in limited use with the USMC. The 590A1 is legendary, and it’s an excellent weapon. Bless them for it. Mossberg has released the 590A1 to general consumers.
There are tons of various 590A1 shotguns out there, in tons of different configurations. The most common commercial configuration has a 20-inch barrel, ghost ring sights, modern polymer furniture, and holds eight rounds. I have one just like that and a Mossberg 590A1 Retrograde. I just really love the 590A1 series and will likely purchase an SBS variant with the 14-inch barrel one of these days.
The 590A1 series are some of the more expensive shotguns on the market. They are widely available, and their variations do affect the price. The Retrograde, in particular, tends to be the most expensive variant on the market outside of NFA models.
Where the Mossberg 590A1 Came From
In the 1970s, the military had a ton of shotguns bouncing around. They had Remington 870s, Winchester Model 12s, Winchester 1200s, Ithaca 37s, and more. To standardize, they put out the call to manufacturers, and the usual suspects showed up. Mossberg had a good shotgun, and it was at a great price. The problem was it didn’t meet all the external requirements.
They called for a magazine tube that could be ‘blown out’ if need be. The Mossberg 500 series doesn’t have that capability. Mossberg modified the Model 500, and it became the M500. According to US Combat Shotguns, the Navy and Coast Guard purchased 5,900 M500 Shotguns.
That must have been the magic number, and Mossberg specifically named the military model the M590. The Navy requested more specifications. They wanted a longer magazine, a bayonet lug, and a thicker, heavier barrel. This became the Mossberg 590A1.
The Retrograde model isn’t a throwback to older 590A1s. It’s a bit of an imaginary retro shotgun. It has wood furniture, ghost ring sights, a bayonet lug, a heat shield, and a parkerized finish. This is not a reference to an older military shotgun by any means.
The 590A1 Difference
We know the military’s request resulted in a heavier barrel. This made it a bit more bombproof and more durable overall. That’s great when dealing with those heavy metal doors on ships and keeping the barrel from getting bent. That’s not a problem for you and me, so what’s the point of the heavier barrel?
One nice side effect of the heavier barrel is tighter patterns. I first heard this from Steve Fisher of Sentinel Concepts. He theorized it had to do with the barrel harmonics of the heavier barrel combined with the bayonet lug and how the barrel attached to the gun. At the end of the day, the why doesn’t matter. In my observation, the Mossberg 590A1 patterns are anywhere from 20% to 50% tighter than a standard shotgun.
The 590A1 guns also come with a metal trigger system. It’s quite nice to have a full metal trigger system for durability’s sake. I do think it’s a better trigger in terms of pull, but I’ve also shot my 590A1 a ton, so maybe it’s just well-tuned and toned.
At the Range
The 590A1 is a beastly shotgun. If you want short and light, this isn’t for you. There are plenty of non-NFA tactical shotguns out there that are both lighter and shorter than the classic 590A1 series. It’s a fighting shotgun, one designed for war-like encounters, not necessarily police or home defense. You feel that weight, and you might love it or hate it.
I like the weight because shotguns aren’t shy about recoil. The 12 gauge recoil is better mitigated through technique, but a heavier gun and good technique make life easy. Another side benefit of that heavy barrel is less muzzle rise per shot. It’s easier to keep on target, especially when rapidly firing the gun.
I can keep it on target as I empty the entire magazine tube of full-powered buckshot. This makes it easy to control the weapon and is pretty valuable for any soldier, sailor, or Marine in a firefight. It’s also great for home defense or any fast shooting you need to do.
The ghost ring sights on both my 590A1 models make the gun easy to shoot straight. You can aim decently quick at close range and take some precise shots at 50 to even 100 yards with slugs. The patterns are quite tight. Even with basic buckshot, it outperforms most basic bare-bones shotguns to an impressive degree.
Like all modern pump shotguns, you won’t run into reliability problems with the 590A1. It handles any 2.75 and 3-inch shells with ease. It shucks and bucks ’em without much worry. You can blast away without concern that the next round will load and fire.
Role and Purpose of the 590A1
Is the 590A1 worth the extra weight and cost when compared to a standard 590? That’s a tough call. As a shotgun nerd, I think it’s worth it if you’re a shotgun nerd. A tight pattern is handy for home defense, but you can get an even tighter pattern with proper ammo. Federal FliteControl, for example, provides a much tighter pattern than any other load. The Flitecontrol load doesn’t get any tighter from a 590A1 barrel.
It is heavier and longer than most shotguns, and in-home defense, that can be a pain. A lighter standard 590 with an 18.5-inch barrel might make a little more sense for home defense. Plus, if you ditch the bayonet lug, you don’t get any issues from a pump-mounted shotgun light. It’s a minor issue but one worth noting.
A 590A1 won’t serve you wrong for home defense, but it might not be optimum. If you want a bombproof, well-made, and durable as-all-get-out shotgun, then the 590A1 certainly fills that role. It’s tough, durable, and well-made. It’s perfect if the world ends, especially with a bayonet. Who doesn’t love a bayonet?
