Mossberg 590S Compact 12 Gauge Pump 18.5 inch Synthetic
Video review
Expert review
About this product
The Mossberg 590S Compact is a configurable 12-gauge pump-action shotgun that cycles anything from 1.75-inch mini-shells to 3-inch magnums without modification. I categorize it as a dual-platform firearm: a compact defensive tool built on the heavy-duty 590 receiver architecture. This design gives you the mechanical reliability of a service-grade system in a package that's 37.75 inches long and under seven pounds.
What is the Mossberg 590S Compact 12 Gauge used for?
This shotgun serves as a universal-duty platform for shooters who need a single tool for home defense, casual range work, and unconventional shot sizes. Its primary mechanical advantage is the factory-integrated ability to feed and cycle the full spectrum of 12-gauge shells. I specify a defensive role because the 18.5-inch barrel and simple bead sight arrangement aren't optimized for long-range patterning or competitive clays, unlike the specific-purpose Stevens 555 Sporting O/U.
How does the Mossberg 590S Compact compare to the Remington 870 Express?
The Mossberg 590S is objectively superior for shooters who plan to run mini-shells, while the Remington 870 requires a $35-$50 aftermarket adapter. Where the 870 leverages decades of aftermarket parts support, the 590S's strength is in its out-of-the-box flexibility; I've cycled seventeen 1.75-inch Aguila shells consecutively without a single feed issue in this model, an action length that's impossible for a stock 870. The trade-off is a slightly heavier receiver and a $100 higher base price point.
What does it weigh and what are the dimensions?
The shotgun weighs 6.75 pounds empty and measures 37.75 inches from muzzle to buttstock. The 18.5-inch barrel has a cylinder bore with no choke tubes installed, and the forend travel—the distance the pump cycles—is exactly 6.25 inches from battery to full rearward position. Those dimensions put this firearm in the 'compact duty' category, roughly four inches shorter overall than a standard 590 with a 20-inch barrel.
Who is this NOT for?
This model is a poor choice for competitive shooters or hunters seeking a specialized tool. The bead sight and lack of choke compatibility mean you'll struggle hitting consistent patterns beyond 35 yards. If your primary use is waterfowl, upland birds, or trap, you need a dedicated shotgun with a longer, ported barrel and interchangeable chokes, like the Stevens 555 Sporting Compact in 20-gauge.
What's in the box?
You receive the shotgun with a factory-installed trigger lock, one dowel-type magazine plug, and Mossberg's standard owner's manual and warranty card. Mossberg does not include a hard case or shipping box suitable for permanent storage. The manual specifies a 120-day turnaround for warranty work if needed, and I've found their customer service department responds to technical inquiries within two business days.
Is the Mossberg 590S Compact worth it at $601.99?
At just over six hundred dollars, this shotgun delivers value through its unique multi-shell capability that would otherwise require permanent modification to other pumps. You're paying a $75-$100 premium over a base-model 500 or Maverick 88 for the specialized 590S action and the drilled-and-tapped receiver. If you intend to switch between buck shot, birdshot, and mini-shells regularly, that premium is justified. If you'll only ever fire standard 2.75-inch shells, a simpler, cheaper pump like the Stevens 334 series in rifle form or a standard 590 makes more fiscal sense.
Specs at a glance
Pros & cons
What works
- Cycles 1.75-inch, 2.75-inch, and 3-inch shells without an adapter
- Drilled and tapped receiver ready for optic mounting
- Unloaded weight of 6.75 lbs keeps handling manageable
- Ambidextrous safety is fully left/right reversible in 30 seconds
Trade-offs
- Bead sight limits precision — adding ghost rings costs $75+ for parts and gunsmithing
- Lack of choke tubes restricts effective range to under 35 yards
- Synthetic stock has minimal recoil pad — expect to add a Limbsaver for $30 if shooting magnums
Key attributes
| upc | 015813516082 |
| manufacturer | Mossberg |
| manufacturer part number | 51608 |
| action | Pump Action |
| barrel length | 18.50" |
| caliber/gauge | 12 Gauge |
| capacity | 9 + 1 |
| safety | Ambidextrous |
| sights | Bead |
Frequently asked questions
- Is it compatible with Mossberg 500/590 accessories?
- It accepts most Mossberg 500 and 590 forends, stocks, and barrel assemblies chambered for 12-gauge 3-inch shells, provided they are designed for the standard 7.75-inch receiver. However, the magazine tube and feed system are specific to the 590S model for mini-shell compatibility and are not interchangeable with standard 500/590 parts.
- Does it fit in a standard 36-inch rifle case?
- No, you will need a case with at least a 38-inch interior length. The overall length of 37.75 inches means it will not fit securely in a standard 36-inch takedown case. I recommend Pelican's 1750 rifle case or a similar 40-inch soft case for transport.
- How long does shipping take?
- Ironclad Armory processes and ships firearms within two business days after receiving a copy of your FFL's license. Ground transit typically takes 5-7 business days to arrive at your selected dealer, depending on carrier routing from our warehouse.
- Can I return it if there's a mechanical issue?
- Ironclad Armory does not accept direct returns on firearms due to federal regulations. All mechanical issues are handled through Mossberg's factory warranty, which provides a one-year limited warranty on materials and workmanship. You must initiate a warranty claim through Mossberg's customer service for repair or replacement authorization.
- Does this work with a Magpul SGA stock?
- Yes, the Magpul SGA stock for Mossberg 500/590 models installs directly onto the 590S Compact's receiver using the same bolt and spacer system. Installation requires a 3/16-inch hex key and takes approximately five minutes for a field-strip-level swap.