Mossberg 590A1 M-Lok 18.5" 12ga Shotgun 3" Pump Blk - 50766

Mossberg 590A1 12ga Pump Shotgun 18.5" M-Lok 3" Chamber Black - Model 50766

Mossberg
SKU:
120918052
|
UPC:
015813507660
|
MPN:
50766
$612.23
$770.00
(You save $157.77 )
Current Stock:
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Product Specifications
Capacity-Rounds:
6
Caliber-Gauge:
12 Gauge
Hand:
Right Hand
Barrel Length:
18.5"
Barrel Length Range:
18" to 18.99"
OAL:
39.50"
Chamber:
3"
Weight:
7 lbs
Metal Finish Group:
Blued/Black
Action:
Pump
Stock Finish Group:
Black
Metal Finish:
Black Parkerized
Sights:
Bead Front
Weight Range:
7 lbs to 7.99 lbs
Barrel Description:
Heavy-Walled
Product Overview

The Mossberg 590A1 is a proven 12-gauge pump shotgun built to handle serious work. With an 18.5" barrel, 3" chamber, and M-Lok foregrip compatibility, this is a no-nonsense home defense and tactical shotgun that meets MIL-SPEC 3443G standards—the same durability spec that made it a workhorse for military and law enforcement. If you want a shotgun that prioritizes reliability and endurance over frills, the 590A1 delivers.

What sets the 590A1 apart is its heavy-walled barrel construction and steel-to-steel lockup, paired with dual extractors and twin action bars to keep the gun cycling reliably under stress. The metal trigger guard and safety won't flex or fail, and the Parkerized finish resists corrosion in harsh conditions. The receiver is drilled and tapped so you can mount optics or add accessories as your needs evolve. The clean-out magazine tube design makes maintenance straightforward—no hidden debris traps.

The ambidextrous top-mounted safety sits where your thumb naturally rests, and the anti-jam elevator keeps rounds feeding smoothly even in rapid-fire sequences. This is field-proven platform that's been trusted for decades, and the M-Lok rail system gives you modern attachment options for lights, grips, or other gear. Whether you're setting up for home defense, patrol, or serious shotgun sport, the 590A1's reputation for durability and simplicity speaks for itself.

Key Features

  • MIL-SPEC 3443G construction for military-grade durability and reliability
  • Heavy-walled barrel resists wear and deformation under heavy use
  • 18.5" barrel with 3" chamber for standard and magnum loads
  • M-Lok compatible foregrip for mounting lights, grips, or tactical accessories
  • Dual extractors and steel-to-steel lockup for consistent performance
  • Twin action bars for smooth, jam-resistant operation
  • Ambidextrous top-mounted safety for quick, intuitive handling
  • Anti-jam elevator prevents feeding problems
  • Clean-out magazine tube for easy maintenance
  • Drilled and tapped receiver ready for optics mounts
  • Metal trigger guard and safety—no plastic components to fail
  • Parkerized finish for corrosion resistance

Specifications

Gauge12
Barrel Length18.5"
Chamber3"
ActionPump/Slide
Rail SystemM-Lok
FinishParkerized (Black)
Model Number50766
ReceiverDrilled and Tapped
ExtractorsDual
Action BarsTwin
SafetyAmbidextrous Top-Mounted

Frequently Asked Questions

What's the difference between the 590A1 and other Mossberg pump shotguns?

The 590A1 is built to MIL-SPEC 3443G standards, meaning it meets military durability and reliability requirements. The heavy-walled barrel, dual extractors, steel-to-steel lockup, and all-metal trigger guard and safety separate it from lighter-duty models. It's engineered for sustained, demanding use.

Can I mount optics or lights to the 590A1?

Yes. The receiver is drilled and tapped for optics mounts, and the M-Lok foregrip rail lets you attach tactical lights, grips, and other accessories. You have modern customization options out of the box.

What ammunition does the 590A1 shoot?

The 3" chamber handles both standard 2.75" and magnum 3" shotgun shells in 12 gauge. Verify your specific load selection with ammunition manufacturers for compatibility with your intended use.

Is the 590A1 good for home defense?

Yes—the 18.5" barrel makes it maneuverable indoors, the short length suits tight spaces, and the MIL-SPEC construction ensures reliability when it matters. The pump action and ambidextrous safety are intuitive under stress. Many home defense setups use the 590A1 platform for exactly these reasons.

Additional Information

Firearm Shipments:

To buy rifles or shotguns, you must be 18 years old, and for handguns, actions, or receivers, the minimum age is 21. By placing an order for this firearm, you confirm that you are the legitimate transferee/buyer, meet the legal age requirements, and comply with all Federal, State, and local laws and regulations necessary to purchase this firearm.

We only ship firearms to valid Federal Firearms License (FFL) holders. At checkout we provide a FFL locator for your convenience.

We will need a copy of the FFL’s license to facilitate the process, kindly request your dealer to email us a copy of their FFL, as we cannot dispatch the firearm until we receive this document. It is imperative for the buyer to choose their FFL dealer, ensure they are willing to facilitate the transfer, and have them email their FFL copy to BOSQUE Outdoors. To avoid any confusion, the customer's name or order number must be mentioned in the email containing the FFL.

Email: [email protected]

  • Prior to placing an order, it is the buyer's responsibility to understand and adhere to their state's firearm regulations.
  • The buyer should verify with their receiving dealer that the chosen firearm is legally permissible in their state.
  • The buyer is accountable for any transfer fees or background check charges imposed by the receiving dealer. If the designated dealer declines to accept the firearm delivery, the buyer assumes responsibility for shipping costs to retrieve the firearm and resend it to an accommodating dealer.
  • Handguns will be shipped using air transportation, while long guns can be shipped using ground methods. If your order includes a mix of firearm and non-firearm items, BOSQUE Outdoors will send the firearm(s) to your selected FFL dealer and the remaining non-firearm items to your billing address.
  • Firearms cannot be returned to BOSQUE Outdoors; please contact the manufacturer for warranty claims.
  • Firearms refused by the FFL Dealer or which cannot be transferred due to a failed background check are subject to a $75 restocking fee plus 10% of the purchase price.