590M Shockwave
The new 590M Shockwave comes with a 10-round magazine. You can also buy mags with 5-, 15-, and 20-round capacities. Mossberg

Last year, Remington released its non-NFA shorty shotgun as the TAC-14 DM as part of its new line of 870 shotguns with detachable box magazines. At SHOT Show 2018, Mossberg released it’s own box-fed pump gun with the 590M, but the release was more about capacity than portability, and a short version was nowhere to be seen.

Today, Mossberg announced it’s own shorty box-fed pump gun: the 590M Shockwave in 12 gauge.

The shotgun has a 15-inch barrel, Shockwave Technologies Raptor pistol grip, and a double-stack, 10-round magazine (2.75-inch shells).

The new Shockwave will also accept 5, 10, 15, and 20-round magazines from Mossberg, which can be purchased separately.

The gun has all the standard features of the regular 590 Shockwave, icnluding twin action bars, dual extractors, an anodized aluminum receiver drilled and tapped for optics or an accessory rail, a heavy-walled barrel, easy-to-clean magazine tube (which is still necessary because the slide needs something to be mounted to), and an inherently ambidextrous top-tang safety.

The shotgun has an overall length of 27.5 inches, and weighs in at 6.55 pounds, unloaded.

For a refresher, the reason you don’t need a tax stamp to own a Shockwave or a TAC-14 is because it is classified by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATFE) as a “non-NFA firearm” meaning it’s not technically a short-barreled shotgun (SBS), because it was never fitted with a shoulder stock. So, you can purchase it per local laws just as you would any long gun.

Many attribute the success of the Shockwave and the TAC-14 to its BATFE classification, but also to the unique pistol grip, which is featured on both firearms.


Feeding shotshells reliably from a box magazine has long been the goal of gunmakers. Find out why it has been such a difficult engineering hurdle.

The Miracle of Detachable Box Magazine Shotguns

From Mossberg:

Unique to the Shockwave platform, and providing its novel moniker, is the Shockwave Technologies Raptor pistol grip.

This well-designed pistol grip features an enhanced textured finish and has a “bird’s head” shaped-profile, allowing for maximum control while minimizing felt recoil. The grip is constructed of durable, glass-filled polymer with non-reflective, black finish and has an overall length of 5.25 inches. Completing the furniture package for the 590M Shockwave is the cob-styled, tactical forend which is strapped for greater control and smoother operation.

As a first for mag-fed shotguns, the 590M design features a patented double-stack magazine constructed with hardened-steel feed lips, over-molded steel shell ramps and an anti-cant, rounded follower to ensure reliable feeding. Additional features include an easy-grip, molded external shell; proprietary self-lubricating polymer magazine body; heavy-duty ASTM-A-228 music-wire magazine spring for prolonged service life; removable floor plate for ease of cleaning; and durable black oxide finish on the steel components. This proprietary double-stack magazine design provides greater capacity in less magazine length versus competitor’s single stack magazines.


Now that both Big Green and Mossberg have debuted detachable mag versions of their classic pump guns, we take a look at how they stack up.

Mossberg 590M vs. Remington 870 DM

One of the more interesting things about the regular 590 Shockwave is that with 1.75-inch shells like the 12 gauge MiniShells from Aguila, and an adapter that doesn’t work on the TAC_14, the pump gun can hold 8+1 rounds. It holds 5+1 with 2.75-inch shells. The 1.75” shells are particularly forgiving when it comes to recoil in the little shotgun.

The 590M Shockwave beats that capacity, even with its stock magazine, by two shells—plus it has the quick reload capabilities of a detachable box magazine and the ability to increase capacity dramatically with only the purchase of a bigger mag.

But, it can’t run MiniShells, so if recoil is an issue, you’ll have to make due with the softest kicking 2.75-inch loads you can find.

Mossberg 590M Shockwave Specs

  • Gauge: 12 gauge – 2.75 Inch
  • Capacity: 10+1 with included 10-round magazine. 5, 15, and 20-round mags also available
  • Barrel: 15-inch, heavy walled, matte blue
  • Sights: Bead
  • Choke: Cylinder Bore
  • Overall Length: 27.5″
  • Grip: Shockwave Raptor Grip, black synthetic
  • Forend: “Cob” slide with strap, black synthetic
  • Weight: 6.55 lbs.
  • MSRP: $721