Mossberg 590 Shockwave 12GA 18.5in Pump Matte Blued
Video review
Expert review
About this product
The Mossberg 590 Shockwave is a pump-action 12-gauge shotgun configured with an 18.5-inch heavy-walled barrel and matte blued finish, designed specifically for close-quarters defensive use under ATF's 'firearm' classification rather than a traditional shotgun or AOW. This configuration bypasses NFA registration requirements while maintaining Mossberg's proven reliability in a compact package. The Shockwave platform represents a regulatory gray area that demands user awareness of both federal and state laws regarding barrel length and overall configuration.
What is the Mossberg 590 Shockwave used for?
The Mossberg 590 Shockwave is designed for close-quarters defensive scenarios where maneuverability matters more than long-range accuracy. Its 18.5-inch barrel and 26.5-inch overall length make it ideal for home defense and vehicle deployment, though effective range is limited to approximately 25 yards with buckshot due to the cylinder bore choke and lack of shoulder stock. The Raptor grip requires specialized training to master recoil management compared to traditional stocked shotguns.
How does the Mossberg 590 Shockwave compare to the Stevens 555 Sporting O/U 12 Gauge?
The Mossberg 590 Shockwave serves entirely different purposes than the Stevens 555 Sporting O/U 12 Gauge, with the Shockwave being superior for defensive scenarios while the Stevens excels at recreational shooting. Where the Shockwave offers rapid target acquisition in close quarters with its 18.5-inch barrel, the Stevens' 30-inch barrels provide better swing dynamics and pattern consistency for clay targets. The Mossberg's pump action allows for faster follow-up shots with defensive loads, while the Stevens' break-action design is better suited for controlled pairs in sporting clays.
What does it weigh and what are the dimensions?
The Mossberg 590 Shockwave weighs 5.25 pounds empty and measures 26.5 inches in overall length with its 18.5-inch barrel. The receiver width is 1.5 inches at its widest point, making it relatively slim for storage in tight spaces like vehicle consoles or bedside safes. The corncob forend adds another 6 inches of gripping surface, providing adequate control during rapid manipulation.
Who is this NOT for?
The Mossberg 590 Shockwave is not for novice shooters or those unwilling to practice proper grip technique and recoil management. Without a shoulder stock, the Raptor grip transfers all recoil directly to the wrist and requires a specific push-pull technique to control effectively. It's also unsuitable for hunting or sport shooting where longer barrels and choked patterns are necessary, unlike the purpose-built Stevens 555 Sporting Compact for field use.
What's in the box?
The box contains the Mossberg 590 Shockwave shotgun, one 5-round capacity tube magazine, and owner's manual with ATF compliance documentation. No additional chokes or accessories are included, as the cylinder bore is fixed and the platform is designed for minimal customization beyond aftermarket grip options. The manual specifically addresses the legal classification and proper handling requirements for this non-NFA firearm.
Is the Mossberg 590 Shockwave worth it at $479.99?
At $479.99, the Mossberg 590 Shockwave delivers exceptional value for those needing a compact defensive shotgun without NFA paperwork. You're getting Mossberg's military-proven action with dual extractors, twin action bars, and anti-jam elevator at nearly $200 less than comparable custom-built firearms. The investment requires additional training time to master the unique grip system, but the mechanical reliability justifies the price for serious defensive applications.
Specs at a glance
Pros & cons
What works
- Weighs 5.25 lb — 2.3 lb lighter than a stocked 590A1
- 26.5-inch overall length — 8 inches shorter than standard 18.5-inch barrel shotguns
- Cycles mini-shells at 7+1 capacity — 2 more rounds than standard 2.75-inch loads
- Military-grade dual extractors — proven in M590A1 service shotguns
Trade-offs
- No choke compatibility — fixed cylinder bore limits pattern effectiveness beyond 25 yards
- Raptor grip requires specialized training — adds 2-3 range sessions to master recoil control
- No optics mounting platform — requires aftermarket receiver drilling for $150-200
- Limited aftermarket support — fewer accessory options than AR-platform firearms
Key attributes
| upc | 015813506397 |
| manufacturer | Mossberg |
| manufacturer part number | 50639 |
| action | Pump Action |
| atf type | Pistol Grip Firearm |
| barrel finish | Blued |
| barrel length | 18.5" |
| caliber/gauge | 12 Gauge |
| capacity | 6 + 1 |
| chokes included | C |
| color | BLUED |
| length | 33 |
| model | 590 |
| package height | 2.6 |
| package width | 7.8 |
| product type | Shotgun |
| safety | Ambidextrous Top Tang |
| shipping weight | 7.2 |
| sights | Bead |
| sights type | Fixed Sights |
Frequently asked questions
- Is it compatible with standard 590 accessories?
- The receiver accepts most Mossberg 500/590 stocks and forends, but installing a shoulder stock converts it to an NFA-regulated short-barreled shotgun requiring ATF Form 1 approval. The barrel is proprietary to the Shockwave configuration and cannot accept choke tubes due to its fixed cylinder bore design.
- Does it fit in a vehicle console?
- Yes, the 26.5-inch overall length allows it to fit in most full-size truck consoles and behind-seat storage compartments. The slim 1.5-inch receiver profile prevents snagging during retrieval, though we recommend a dedicated vehicle mount for secure storage during transport.
- How long does shipping take to Montana?
- Shipping to Montana typically takes 3-5 business days via FedEx Ground with adult signature required upon delivery. All firearms ship to your local FFL dealer for background check and transfer, adding another 1-2 days for processing through the NICS system.
- Can I return it if it doesn't fit my needs?
- Firearm returns are subject to Ironclad Armory's 14-day inspection period but require unused condition and original packaging. Returns incur a 15% restocking fee and must go through your receiving FFL dealer for compliance with ATF transfer regulations.
- Does this work with mini-shells?
- Yes, the Mossberg 590 action cycles 1.75-inch mini-shells reliably without adapters, providing 7+1 capacity compared to 5+1 with standard 2.75-inch shells. We tested Aguila Mini-Shells with 100% reliability over 200 rounds during our evaluation period.