The Mossberg 990 Aftershock SPX is a semi-automatic 12-gauge shotgun built for shooters who need a compact, maneuverable platform without sacrificing capability. With an 18.5" barrel and a 7-round magazine capacity, this tactical shotgun delivers the firepower and control you'd expect from a modern security or home-defense tool. The short overall length of 30.875" makes it ideal for tight spaces and quick handling, while the 3" chamber gives you flexibility with standard and magnum loads.
What sets the 990 Aftershock SPX apart is its thoughtfully engineered feature set. The integrated heat shield on the forend keeps your hands protected during extended use, while M-LOK slots across the magazine tube and forend let you mount lights, grips, and other accessories exactly where you need them. Quick-detach ports add another layer of modularity for modern tactical builds. The optic-ready receiver accepts Shield RMSc-footprint red dots, with adapter plates included for RMR, Docter, and Leupold mounts—so you're not locked into one sight system.
Mossberg engineered the 990 Aftershock SPX with real-world usability in mind. The enlarged, beveled loading port reduces fumbles when you're reloading under stress. The knurled charging handle and oversized safety and bolt release are easy to manipulate, even with gloves. A winged front fiber-optic sight comes standard, keeping you on target without relying on optics alone. Inside, the gas system and internal components are treated for corrosion resistance—important for a shotgun that might live in a truck or see regular use. At 6.29 lbs, it's light enough for all-day carry without feeling flimsy.
The 990 Aftershock SPX ships with a Cylinder Bore Accu-Choke already installed, and Mossberg's quick-change choke system lets you swap patterns for different tasks. Whether you're training, hunting, or securing a property, this is a no-nonsense semi-auto that rewards a shooter who values ergonomics and modularity.
| Gauge | 12 |
| Action Type | Semi-Automatic |
| Chamber Size | 3" |
| Barrel Length | 18.5" |
| Barrel Finish | Matte Blue |
| Overall Length | 30.875" |
| Magazine Capacity | 7+1 |
| Weight | 6.29 lbs |
| Choke System | Accu-Choke; Cylinder Bore installed |
| Sights | Winged Front Fiber Optic; Optic-Ready |
| Stock | AfterShock Grip |
The 990 Aftershock SPX is optic-ready with a Shield RMSc footprint receiver and ships with three adapter plates, allowing you to mount red dots designed for RMR, Docter, and Leupold footprints.
The 990 Aftershock SPX uses Mossberg's Accu-Choke System. It ships with a Cylinder Bore choke installed, and you can swap chokes to match your shooting application.
Yes. The compact 18.5" barrel, short 30.875" overall length, easy-to-manipulate controls, and tactical feature set make the 990 Aftershock SPX well-suited for security and home-defense roles. The integrated heat shield, M-LOK accessory slots, and optic-ready design also support modern tactical builds.
The forend and magazine tube both feature M-LOK slots, allowing you to mount lights, vertical grips, rail sections, and other M-LOK-compatible accessories. The shotgun also has quick-detach ports for easy swaps.
Mossberg
