The Mossberg 590M Mag-Fed is a pump-action 12 gauge shotgun notable for one feature that sets it apart from most pump guns: a double-stack detachable magazine. That design enables a 10+1 capacity and faster reloads compared to traditional tube-fed pumps, while keeping the familiar pump-action manual of arms. 
 

Key Specifications 

• SKU: 21905571 
• UPC: 015813502054 
• Brand: Mossberg 
• Model Name: 590M Mag-Fed 
• MPN: 50205 
• Gauge: 12 GA 
• Chamber Length: 2.75" 
• Action Type: Pump Action 
• Capacity: 10+1 rounds 
• Barrel Length: 18.5 inches 
• Overall Length: 39.5 inches 
• Weight: 7.75 lbs 
• Sights Type: Front Bead 
• Stock Material: Synthetic 
• Finish Color: Blued 
   

Detailed Features 

• Double-stack detachable magazine — the first production double-stack shotgun magazine — improves capacity and reload speed over tube-fed designs. Optional magazines available in 5, 10, 15, and 20-round capacities. 
• Heavy-walled barrel construction supports extended use. 
• Corn cob forend provides a positive grip for cycling the action. 
• Removable floor plate and clean-out tube simplify magazine maintenance. 
• Synthetic stock keeps weight manageable and handles weather exposure without swelling or warping. 
   

Usage Scenarios 

• Home defense: the pump action is mechanically simple under stress, and the 10+1 capacity exceeds most tube-fed alternatives. 
• Competitive shooting: detachable magazine reloads are faster than tube reloads for stages that require them. 
• Field use: the 18.5" barrel at 39.5" overall length is maneuverable, and the synthetic stock holds up to rough conditions.

The Mossberg 590M Mag-Fed draws a mix of support and skepticism, with opinions splitting fairly cleanly on the value of the magazine-fed concept.

Supporters appreciate the versatility of the detachable magazine system. Faster reloads and swappable capacity options (5, 10, 15, or 20 rounds) are the most frequently cited advantages over traditional tube-fed pumps. Mossberg's reputation for pump-action reliability carries over to the 590M in most user reports, with owners noting consistent function across conditions. Ergonomics get positive marks — the grip and overall handling feel familiar to anyone experienced with the 500/590 series. Capacity at 10+1 is a genuine improvement for defensive applications. The blued finish and overall construction are well-regarded for durability.

Criticism centers on a few consistent areas. Weight at 7.75 lbs. is on the heavier end for a pump shotgun. Magazine availability and compatibility come up regularly — some users report difficulty sourcing spare magazines or experience inconsistent function with certain third-party options. Transitioning from traditional pump technique to the mag-fed reload takes practice. Price sits above standard 590 variants, and some buyers question whether the magazine system justifies the premium. No 5xx server errors encountered.