Mossberg 590 Shockwave 12 Gauge
Model: 50659
Mossberg 590 Shockwave 12 Gauge
Model: 50659
Full Specifications
About This Firearm
The Mossberg 590 Shockwave is federally classified as a "firearm," not a shotgun. The 14.375-inch barrel and Raptor bird's head grip keep it below any NFA category — no short-barreled shotgun stamp, no suppressor paperwork — because the overall length of 26.37 inches clears the federal 26-inch threshold and it was never manufactured with a shoulder stock. It's a compact 12 gauge for vehicle storage, a boat locker, or anywhere a full-length shotgun won't fit. The 590 platform underneath is the same aluminum alloy receiver, dual extractors, steel-to-steel lockup, and twin action bars that run on the standard Mossberg 590. The ambidextrous top-tang safety is easier to operate from the grip without a stock than the cross-bolt safety on the TAC-14.
At 84 oz (5.25 lbs) and 26.37 inches, the Shockwave is lighter than the Remington 870 TAC-14 (89.6 oz) at essentially the same overall length, a direct consequence of the aluminum alloy receiver versus the TAC-14's steel receiver. Capacity is 5+1 with standard 2-3/4-inch shells — one more round than the TAC-14. The corn cob forend with retention strap is a practical detail for keeping the support hand in place under recoil without a stock to brace against. Mossberg's 590 aftermarket for stocks and accessories is extensive, and the Shockwave-specific accessory market has grown steadily since 2017 when ATF issued the letter that clarified its legal status.
Best For
Strengths & Limitations
- Lightest in the non-NFA compact class at 84 oz — 5.6 oz lighter than the Remington 870 TAC-14 at essentially the same 26-inch overall length, due to the aluminum alloy receiver.
- 5+1 capacity with standard shells beats the TAC-14's 4+1. The corn cob forend with retention strap keeps the support hand secure without a stock under recoil.
- Ambidextrous top-tang safety is faster to operate from the bird's head grip than a cross-bolt safety — thumb access is natural from either hand without changing grip position.
- No optic rail from the factory, and the receiver isn't drilled and tapped — adding a red dot requires a clamp-on rail mount that attaches to the barrel or receiver via the existing hardware.
- State laws vary significantly for these firearms. Some states classify any sub-18-inch barrel as an SBS regardless of overall length or NFA classification. Verify your state's law before purchasing.
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Frequently Asked Questions
Can I add a shoulder stock to the Shockwave to make it easier to shoot?
No. Adding a shoulder stock would reclassify it as a short-barreled shotgun under the NFA, which requires a $200 tax stamp and ATF approval before the modification — not after. The Shockwave's "firearm" classification is specifically because it was manufactured without a stock. There are arm brace options (under ATF's current rules) that some owners add, but these occupy a regulatory gray area that has shifted over time. Check current ATF guidance before going that route.
Does the Shockwave work with mini shells or reduced-recoil loads?
Reduced-recoil loads work well and are the most common recommendation for new Shockwave owners — standard 00 buck is sharp without a stock. Mini shells (1-3/4-inch) require an OPSol Mini-Clip adapter to feed reliably from the Mossberg 500/590 family. Without the adapter, short shells will typically fail to feed. The OPSol adapter runs about $20 and snaps into the loading port without tools.
