Monstrum Mossberg 500/590 Series Shotgun Picatinny Rail Mount Instruction Manual

Introduction

This manual provides instructions for the installation, operation, and maintenance of the Monstrum Picatinny Rail Mount designed for Mossberg 500 and 590 Series shotguns. This rail allows for the secure attachment of Picatinny or Weaver standard optics such as scopes, red dots, and magnifiers.

A black Monstrum Picatinny rail mount, viewed from a slight angle, showing the rail segments and the Monstrum logo.

Compatibility

This rail mount is specifically designed for Mossberg 500 and 590 Series shotguns. Please verify your shotgun's model and receiver type before installation.

An image detailing compatible and non-compatible Mossberg shotgun models for the Monstrum Z80 Picatinny rail mount. Compatible models include Mossberg 500, 535, 590, 590 Shockwave, 590A1, 835, 930, and 935. Non-compatible models or those requiring modifications include pre-1997 Mossberg shotguns, Mossbergs without pre-drilled and tapped receivers, Mossberg Maverick 88, Mossbergs with Crimson Trace LS250 installed, and Mossberg 500 Flex.

Compatible With:

• Mossberg 500
• Mossberg 535
• Mossberg 590
• Mossberg 590 Shockwave
• Mossberg 590A1
• Mossberg 835
• Mossberg 930
• Mossberg 935

Not Compatible With (or Requires Modification):

• Pre-1997 Mossberg Shotguns (requires 6x48 screws, not included)
• Mossbergs without pre-drilled and tapped receivers (requires drilling and tapping receiver)
• Mossberg Maverick 88 (requires drilling and tapping receiver)
• Mossbergs with Crimson Trace LS250 installed (requires M4-.70 x 12 screws, not included)
• Mossberg 500 Flex (requires modifications)

Setup and Installation

The Monstrum Picatinny Rail Mount is designed for straightforward installation using the existing factory mounting holes on your Mossberg shotgun receiver.

Required Tools:

• Small hex key or screwdriver (typically included with the rail mount)
• The provided set screws

Installation Steps:

1. Ensure the shotgun is unloaded and safe before beginning any installation.
2. Identify the factory mounting holes on the top of your Mossberg shotgun receiver.
3. Align the Monstrum Picatinny rail mount with these receiver mounting holes.
4. Insert the provided set screws into the holes, ensuring they engage the receiver threads.
5. Hand-tighten all screws initially to ensure proper alignment.
6. Gradually tighten each screw evenly until the rail is securely fastened to the receiver. Avoid over-tightening to prevent stripping threads.

The underside of the Monstrum Picatinny rail mount, showing the four recessed screw holes for attachment to a shotgun receiver.

A top-down view of the Monstrum Picatinny rail mount, highlighting the uniform rail segments for accessory attachment.

Operating Instructions

Once installed, the Picatinny rail provides a standard interface for mounting various accessories.

Attaching Optics and Accessories:

1. Ensure your optic or accessory has a Picatinny or Weaver compatible mounting system.
2. Align the accessory's mount with the rail segments on the Monstrum rail.
3. Secure the accessory to the rail according to its manufacturer's instructions.
4. Verify that the accessory is firmly attached and does not wobble before use.

The rail is crafted from lightweight aluminum, providing a stable platform for your chosen optics.

Maintenance

To ensure the longevity and performance of your Monstrum Picatinny Rail Mount, follow these maintenance guidelines:

• Regularly inspect the rail and mounting screws for any signs of loosening or damage.
• Clean the rail with a soft, dry cloth to remove dust and debris.
• Avoid using harsh chemicals or abrasive materials, which can damage the finish.
• If exposed to moisture, dry the rail thoroughly to prevent corrosion.

Troubleshooting

Rail Does Not Fit:

Ensure your shotgun model is listed as compatible in the Compatibility section. Pre-1997 Mossberg shotguns or those without pre-drilled receivers may require professional gunsmithing for installation.

Screws Do Not Align:

Double-check that the rail is correctly oriented and aligned with the factory mounting holes on the receiver. If issues persist, ensure you are using the correct screws for your specific Mossberg model. Some users have reported needing slightly longer screws for certain rear mounts; if this is the case, contact Monstrum support for assistance.

Accessories Do Not Mount Securely:

Verify that your accessory's mount is compatible with Picatinny/Weaver standards. Ensure all accessory mounting screws or levers are tightened according to the accessory's instructions.

Specifications

Warranty and Support

Monstrum offers a lifetime guarantee on all products. If your product fails in any way, contact Monstrum Tactical with your order number for repair or replacement.

For further assistance or inquiries, please contact Monstrum Tactical directly through their official channels or the retailer where the product was purchased.

Seller: Monstrum Tactical