The Mossberg 590 Shockwave is a 20-gauge pump-action firearm with a 14.38-inch barrel, Raptor birdshead grip, and Crimson Trace Laser Saddle. At 5.75 lbs, it is a compact, maneuverable package designed for close-range defensive use. The overall length falls under 26 inches, which makes it legally a "firearm" under the NFA rather than a short-barreled shotgun, provided the owner follows applicable state and local regulations. 
 

Key Specifications 

• Manufacturer: Mossberg 
• Model: 590 Shockwave 
• Gauge: 20 GA 
• Action: Pump Action 
• Capacity: 5+1 Rounds (total) 
• Barrel Length: 14.38 inches 
• Weight: 5.75 lbs. 
• Finish: Matte Black 
   

Detailed Features 

 
The Raptor birdshead grip is shaped to allow one-handed retention and the short-stroke pump action cycles quickly once the technique is learned. The Crimson Trace Laser Saddle mounts over the barrel and provides a visible aim point in low light without requiring a stock or traditional sight picture. Bead sights are present as a backup. The heavy-walled barrel handles standard 20-gauge defensive loads. The ambidextrous safety is accessible from either side of the receiver.

Owners of the 590 Shockwave in 20 gauge generally appreciate the compact dimensions and the practicality of the birdshead grip for storage in a vehicle or small space. The 20-gauge choice over 12 is frequently cited as a deliberate decision -- less recoil to manage without a stock, without meaningfully compromising defensive effectiveness at close range.

The laser saddle gets consistent positive feedback for low-light target acquisition, though a few owners mention it needs to be zeroed carefully.

Recoil without a shoulder stock is the main point of debate. Most owners report it is manageable with proper technique and 20-gauge loads, but newcomers sometimes underestimate the wrist and forearm impact from a handheld pump in this gauge. Training is a common recommendation alongside purchase.

Regulatory awareness comes up in discussions -- some owners remind others to verify the legality in their specific jurisdiction before purchasing. Nothing about the gun is mechanically controversial; the legal landscape around it is what draws most of the nuanced conversation.