The Mossberg 590 Shockwave is a pump-action firearm chambered in 20 gauge with a 14.375-inch barrel and an overall length of 26.37 inches. It uses a Raptor bird's head pistol grip in place of a traditional stock, which keeps it classified as a "firearm" rather than a short-barreled shotgun under federal law -- no NFA tax stamp required. The heavy-walled barrel has a fixed cylinder bore choke and a front bead sight. A top tang safety provides quick access. 
 

Key Specifications: 

• Brand: Mossberg 
• Model: 590 Shockwave 
• Action: Pump Action 
• Finish: Blued 
• Weight: 4.95 lbs (79.2 oz) 
• Caliber/Gauge: 20 Gauge 
• Chamber Size: 3" 
• Capacity: 6 Rounds (5+1) 
• Barrel Length: 14.375" 
• Overall Length: 26.37" 
• Choke Configuration: Fixed Cylinder Bore 
• Sights Type: Front Bead 
   

Detailed Features 

The pump-action mechanism cycles reliably. The heavy-walled barrel minimizes flex during firing, which helps consistency. The matte blued finish provides some corrosion resistance. The Raptor grip design changes the handling ergonomics substantially compared to a stocked shotgun -- control technique matters more here. 
 
The top tang safety is in a natural position for right-hand use, allowing quick readiness without shifting the grip. 
 

Usage Scenarios 

1. Home Defense: The compact 26.37-inch overall length maneuvers through tight spaces; the 20 gauge delivers real stopping power without the recoil of 12 gauge. 
2. Recreational Shooting: Some owners use it informally at the range. 
3. Field Use: The 20 gauge with cylinder bore is suitable for close-range pest control.

The Mossberg 590 Shockwave gets a lot of attention for its unique configuration, and most owners report satisfaction with it as a compact defensive option.

The 20 gauge choice is frequently praised as the right gauge for this platform. It produces noticeably less recoil than a 12 gauge Shockwave while still delivering useful terminal performance, which makes it more practical for extended use and for shooters who are recoil-sensitive.

The compact size is a consistent positive. At 26.37 inches overall with no stock, it handles well in confined spaces. The pump action is reliable and the build quality meets expectations for Mossberg.

The lack of a traditional stock draws some criticism from users expecting to shoot it like a conventional shotgun. Accurate fire with a pistol-grip-only firearm requires a specific technique that takes deliberate practice to develop. Some users note the Raptor grip takes getting used to. The overall sentiment is that it works well for people who train with it, and less well for those who don't.