If you have a Mossberg 500, you may need to change the pump at some point. This is a relatively easy process that anyone can do. Here are the steps you need to follow to change the pump on a Mossberg 500:
- Make sure the shotgun is unloaded.
- Find the release button on the pump.
- Push the release button and pull the pump forward.
- Disconnect the pump from the receiver.
- Connect the new pump to the receiver.
- Push the pump back into place.
- Test the shotgun to make sure the pump is working properly.
Advance Tips: How To Change The Pump On A Mossberg 500?

If you have a Mossberg 500, you may eventually need to change the pump. This job is not difficult, but it does require some basic tools and knowledge. With a few minutes and this guide, you can easily change the pump on your Mossberg 500.
What You’ll Need:
- A Phillips head screwdriver
- A flat head screwdriver
- A punch or other sharp object
- A new pump (optional)
Instructions:
- First, make sure that your Mossberg 500 is unloaded. Remove the magazine and check the chamber to ensure that it is empty.
- Next, locate the two screws that hold the pump assembly to the receiver. These screws are located just behind the trigger guard, on either side of the receiver.
- Using a Phillips head screwdriver, remove these two screws.
- Once the screws are removed, the pump assembly can be slid off of the receiver.
- Take a look at the pump assembly and locate the small pin that holds the pump handle in place. This pin is located just behind the pump handle.
- Using a punch or other sharp object, drive out the pin that holds the pump handle in place.
- With the pin removed, the pump handle can now be slid off of the pump assembly.
- Take a look at the inside of the pump assembly and locate the pump plunger. This is the part that actually pumps the shotgun.
- Using a flat head screwdriver, depress the pump plunger and hold it in place.
- While holding the pump plunger depressed, slide the pump assembly back onto the receiver.
- Replace the two screws that hold the pump assembly in place.
Your Mossberg 500 is now ready to use.
What Is a Mossberg 500 and How Does the Pump Work
The Mossberg 500 is a series of pump-action shotguns used by military personnel, law enforcement, and civilians alike. The pump action works by having the user “pump” the slide forward and then back, which in turn loads a new shell into the chamber. This pumping action works the same regardless of whether you are changing the pump or not. The pump is located on the top of the gun, and when you move the slide forward and back, it causes the pump to move up and down, loading a new shell into the chamber. When you release the slide, the pump is reset and ready to be used again.
What You’ll Need to Change the Pump on a Mossberg 500
To change the pump on a Mossberg 500, you will need a few tools including a set of screwdrivers, a wrench, an Allen key, and a gunsmithing hammer. You will also need a replacement pump, which can be found at most gun stores. Additionally, you should have some general knowledge of firearms, as you will need to remove the action from the stock, as well as disassemble the gun in order to access the pump assembly. Once the old pump is removed, you can install the replacement and reassemble the gun in the reverse order.
Step-by-Step Instructions for Removing the Old Pump
To begin, ensure your Mossberg 500 is unloaded and cleared. Remove the forend and action bars, then slide the pump assembly forward, away from the receiver. Next, remove the trigger group, which is located in the rear of the receiver and secured by two pins. Once the trigger group is removed, you can unscrew the pump assembly from the receiver, then lift it out. Finally, clean the pump assembly and the receiver with a cloth and lubricant before installing the new pump.
Installing the New Pump on the Mossberg 500

First, you’ll need to make sure the gun is unloaded and the action is open. Next, you’ll need to remove the forend nut with a wrench, taking care not to damage the threads. Once the nut is removed, you’ll be able to slide the forend forward until it separates from the receiver. At this point, you can attach the new pump and slide it back into the receiver. Make sure to tighten the forend nut firmly to ensure the new pump is securely attached.
Checklist of Important Steps to Ensure Proper Installation
Once you have the necessary tools and replacement parts, the most important step in ensuring proper installation is to thoroughly read the manufacturer’s instructions. This will provide detailed guidance on how to properly change the pump, including the specific steps to follow and any safety precautions to keep in mind. Additionally, make sure to inspect the new pump for any defects and confirm that it is compatible with your Mossberg 500. Before beginning the installation, double check that all the necessary parts are on hand. Once the installation is complete, test the pump to make sure it functions properly.
Troubleshooting Common Issues When Changing the Pump
When troubleshooting common issues when changing the pump on a Mossberg 500, it is important to thoroughly inspect all connections and components for signs of wear or damage. Additionally, make sure that the pump is fully seated in the receiver and the action bars are properly aligned before reassembling the shotgun. Lastly, ensure that all screws and pins are properly tightened and that the safety is engaged in the “safe” position before using the shotgun.
Frequently Asked Questions [FAQs]
To remove the old pump from your Mossberg 500, first remove the magazine cap and slide the pump assembly forward. Next, disconnect the action bar assembly from the pump by removing the pin that holds it in place. Finally, remove the old pump from the shotgun by sliding it off the action bars.
To install the new pump on your Mossberg 500, first slide the pump onto the action bars. Next, reconnect the action bar assembly to the pump by inserting the pin that holds it in place. Finally, slide the pump assembly back into the shotgun and replace the magazine cap.
There are several benefits to upgrading your Mossberg 500 pump, including increased reliability, smoother operation, and faster cycling. Additionally, many aftermarket pumps offer additional features such as extended magazine tubes and Picatinny rails for mounting accessories.
Most aftermarket pumps for the Mossberg 500 are compatible with all model variations of the shotgun. However, it is always best to consult with the manufacturer of your particular model to ensure compatibility.
Some of the most popular aftermarket pumps for the Mossberg 500 include the Mesa Tactical Urbino Stock, the Vang Comp Systems Big Mouth Pump, and the Nordic Components NC-1.
Conclusion
If you need to change the pump on your Mossberg 500, first make sure that the shotgun is unloaded. Next, remove the magazine cap and slide the pump forward. To remove the old pump, simply unscrew it from the pump housing. To install the new pump, screw it into the housing and then replace the magazine cap.

A. Wilcox Head is a lifelong shooter, hunter, and firearms enthusiast. Head grew up in a family where firearms were a way of life, and from an early age, he was taught the importance of firearm safety, accuracy, and proper hunting techniques.