Mossberg FLEX Stock Model 500 590 Standard Medium Synthetic DEMO/USED

The Mossberg FLEX Stock for Model 500/590 shotguns is a tool-free way to dial in a better fit on one of the most popular pump-action shotguns in America. Built from synthetic materials for durability and low maintenance, this standard medium-length stock comes with a recoil pad to help manage the bark of a defensive or hunting 12-gauge. Whether you're setting up a home-defense rig, running clay courses, or hunting upland birds, the FLEX system lets you adjust your shotgun's handling without breaking out the toolbox.

What sets the Mossberg FLEX platform apart is its no-fuss compatibility system. You don't need a gunsmith, specialized tools, or an instruction manual to swap stocks on your 500 or 590—just use the clever locking mechanism to secure your chosen setup. That makes it possible to configure different shotguns for different roles, or to fine-tune the length of pull for shooters of different frames without permanent modifications.

This particular unit is a demo or used item, so it carries the real-world character of a shotgun that's been worked. If you're building or refreshing a Mossberg pump and want the flexibility of the FLEX system without paying new-in-box prices, this is a straightforward, functional option.

Key Features

• Tool-free locking system—no gunsmith visit or special equipment needed
• Synthetic construction resists weather and rough handling
• Integrated recoil pad for comfort and noise management
• Standard medium length of pull (13-1/2 inches)
• Exclusive to Mossberg FLEX-compatible 500/590 platforms

Specifications

Frequently Asked Questions

Will this stock fit my Mossberg 500 or 590?

Yes, but only if your shotgun is one of the FLEX-compatible models. The tool-free locking system is proprietary to Mossberg's FLEX platform, so verify your shotgun's FLEX compatibility before ordering.

Do I need tools to install it?

No. The FLEX locking system is specifically designed to be tool-free, so you can swap or adjust it with just your hands.

What's included?

The stock comes with the integrated recoil pad. Check the condition notes for this demo/used unit to confirm all original components are present.

What length of pull does this stock have?

This is a standard medium stock with a 13-1/2-inch length of pull, suited for most shooters of average build.