So, you've got yourself a Mossberg 940 Pro Tactical, huh? Awesome choice! These shotguns are known for their reliability and performance, but like any firearm, they can sometimes run into a few hiccups. Don't sweat it, guys! This guide is here to help you troubleshoot some common issues you might encounter with your 940 Pro Tactical and get you back on the range or in the field in no time. We'll cover everything from failure to feed to cycling problems, so let's dive right in!

Understanding the Mossberg 940 Pro Tactical

Before we jump into troubleshooting, let's quickly recap what makes the Mossberg 940 Pro Tactical tick. This shotgun is a gas-operated, semi-automatic beast designed for tactical applications, competition, and home defense. It builds upon the reliable Mossberg platform with several enhancements, including an improved gas system, enlarged controls, and a durable finish. Knowing its key features will help you diagnose problems more effectively.

• Gas System: The 940 Pro Tactical utilizes a gas system to cycle the action, meaning it uses some of the gas from each fired shell to eject the spent casing and load a new one. This system is designed to be reliable, but it can be sensitive to factors like ammunition type and cleanliness.
• Enlarged Controls: Mossberg upgraded the controls, such as the charging handle and bolt release, to be larger and easier to manipulate, especially under stress or while wearing gloves. These are generally robust but can occasionally be sources of issues if damaged or improperly installed.
• Durable Finish: The 940 Pro Tactical boasts a durable finish designed to withstand harsh conditions and heavy use. While the finish itself is tough, it's still important to maintain the shotgun properly to prevent corrosion and wear.
• Capacity: Typically, these shotguns come with a standard capacity, but extensions can increase the number of rounds you can load. Aftermarket modifications related to capacity can sometimes introduce feeding or cycling problems if not correctly installed.

Knowing these features is the first step in keeping your 940 Pro Tactical running smoothly. Now, let's move on to the common problems and how to fix them.

Common Problems and Solutions

Alright, let's get down to the nitty-gritty. Here are some of the most common problems you might face with your Mossberg 940 Pro Tactical, along with potential solutions:

1. Failure to Feed

Failure to feed is a frustrating issue where the shotgun fails to load a new shell from the magazine into the chamber. This can manifest in a few ways, such as the bolt closing on an empty chamber or the shell getting stuck halfway. Here’s how to tackle it:

First, ensure you're using the correct ammunition. The 940 Pro Tactical is designed to handle a wide range of 12-gauge shells, but it might not reliably cycle very light loads. Try using standard or heavy field loads to see if that resolves the issue. Check the magazine tube for any dents, debris, or obstructions. A damaged or dirty magazine tube can prevent shells from feeding smoothly. Disassemble the magazine tube and clean it thoroughly with a solvent, then lightly lubricate it before reassembling.

Next, inspect the magazine spring and follower. A weak or damaged magazine spring won't provide enough force to push the shells up into the action. Replace the spring if it feels weak or looks damaged. The follower should also be clean and move freely within the magazine tube. If it's sticking, clean it or replace it with an aftermarket follower.

Then, examine the shell latch and lifter. These components are responsible for releasing shells from the magazine and lifting them into the path of the bolt. If they're worn or damaged, they might not function correctly. Check for any signs of wear or damage and replace the affected parts if necessary.

Finally, make sure the chamber is clean. A dirty or fouled chamber can prevent shells from seating properly. Clean the chamber with a chamber brush and solvent to remove any buildup. Remember, keeping your shotgun clean is a must for reliable operation.

2. Failure to Eject

A failure to eject occurs when the spent shell casing isn't fully ejected from the shotgun after firing, often resulting in a jam. This can be caused by several factors, so let's break it down. The most common cause of ejection problems is a dirty or underpowered gas system. The 940 Pro Tactical relies on gas pressure to cycle the action, and if the gas system is dirty or obstructed, it won't generate enough force to fully eject the shell. Disassemble the gas system according to the manufacturer's instructions and clean all components thoroughly with a solvent. Pay special attention to the gas ports in the barrel, as these can become clogged with carbon buildup.

Also, check the ejector and extractor. The ejector is a small part that kicks the shell out of the action, while the extractor is responsible for pulling the shell from the chamber. If either of these parts is worn or damaged, it can cause ejection problems. Inspect the extractor for any chips or cracks and make sure it has a good grip on the shell rim. The ejector should be springy and protrude slightly from the bolt face. Replace any worn or damaged parts.

Ammunition also plays a significant role. Using low-powered or weak ammunition may not generate enough gas pressure to fully cycle the action. Try using higher-powered ammunition to see if that resolves the issue. If you're using reloads, make sure they're loaded to the proper specifications.

Improper lubrication can also cause problems. While it's important to lubricate your shotgun, over-lubrication can attract dirt and debris, which can interfere with the action's smooth operation. Use a light coat of oil on the moving parts, and avoid getting oil in the gas system.

3. Cycling Problems

Cycling problems can manifest as slow cycling, failure to cycle completely, or inconsistent cycling. This means the shotgun isn't reliably loading and ejecting shells, which can be a real pain. First off, make sure your shotgun is clean and properly lubricated. A dirty or dry shotgun will cycle sluggishly, so give it a thorough cleaning and apply a light coat of oil to the moving parts. Pay special attention to the bolt, bolt carrier, and action rails.

Also, check the recoil spring. The recoil spring is responsible for returning the bolt to its forward position after firing. If the spring is weak or damaged, it can cause cycling problems. Replace the recoil spring if it feels weak or looks damaged. Some shooters also experiment with aftermarket recoil springs to fine-tune the cycling of their shotguns.

Another factor to consider is the gas system. As mentioned earlier, the gas system is crucial for cycling the action. Make sure it's clean and free of obstructions. If you're shooting a wide variety of ammunition, you might need to adjust the gas system to optimize it for the specific loads you're using. Some aftermarket gas system components allow for more precise adjustments.

Shooter technique can also play a role. Make sure you're providing a firm shoulder to absorb the recoil. Limp-wristing can cause the shotgun to cycle improperly. A firm grip and solid stance will help ensure reliable cycling.

4. Trigger Issues

Trigger issues can range from a heavy trigger pull to a complete failure of the trigger to function. Obviously, this is a serious problem that needs to be addressed immediately. Start by inspecting the trigger assembly for any signs of damage or wear. Look for broken or bent parts, and make sure all the pins and springs are in their proper locations. If you find any damaged parts, replace them immediately.

Next, clean the trigger assembly thoroughly. Dirt, grit, and grime can accumulate in the trigger assembly and cause it to function improperly. Use a solvent to clean all the components, and then apply a light coat of oil to the moving parts. Be careful not to over-lubricate the trigger assembly, as this can also cause problems.

If the trigger pull is too heavy, you might consider installing an aftermarket trigger kit. These kits typically include lighter springs and polished components that can significantly improve the trigger pull. However, be sure to follow the manufacturer's instructions carefully when installing an aftermarket trigger kit.

Safety is paramount when dealing with trigger issues. If you're not comfortable working on the trigger assembly yourself, take the shotgun to a qualified gunsmith. Never attempt to disassemble or modify the trigger assembly unless you have the necessary skills and knowledge.

5. Magazine Tube Extension Problems

Adding a magazine tube extension can increase the capacity of your Mossberg 940 Pro Tactical, but it can also introduce new problems if not installed correctly. A common issue is failure to feed, which can occur if the extension isn't properly aligned or if the magazine spring is too weak. Make sure the extension is securely attached to the magazine tube and that it's aligned correctly. If the magazine spring feels weak, replace it with a stronger aftermarket spring designed for use with magazine extensions.

Another potential problem is binding or friction between the shells and the inside of the extension. This can prevent the shells from feeding smoothly. Clean the inside of the extension with a solvent and then apply a light coat of lubrication. You might also consider using a high-quality follower designed for use with magazine extensions.

Ammunition selection can also play a role. Some types of ammunition might not feed as reliably in magazine extensions as others. Experiment with different types of ammunition to see what works best in your setup. You might also consider polishing the inside of the extension to reduce friction.

Lastly, regularly inspect the magazine tube extension for any signs of damage or wear. A loose or damaged extension can cause serious problems, so it's important to catch any issues early. Make sure all the components are securely attached and that the extension is properly aligned.

Maintenance Tips for Longevity

To keep your Mossberg 940 Pro Tactical running smoothly for years to come, regular maintenance is key. Here are some essential tips:

• Clean Regularly: After each shooting session, clean your shotgun thoroughly. Disassemble it according to the manufacturer's instructions and clean all the components with a solvent. Pay special attention to the barrel, gas system, and bolt. Remove any carbon buildup, fouling, or debris.
• Lubricate Properly: Apply a light coat of oil to the moving parts of your shotgun. Avoid over-lubrication, as this can attract dirt and debris. Use a high-quality gun oil designed for firearms.
• Inspect Regularly: Before each shooting session, inspect your shotgun for any signs of damage or wear. Check the barrel, receiver, stock, and all the internal components. Replace any worn or damaged parts immediately.
• Store Properly: When not in use, store your shotgun in a clean, dry place. Use a gun case or safe to protect it from the elements and prevent unauthorized access. Consider using a dehumidifier to prevent rust and corrosion.
• Use Quality Ammunition: Using high-quality ammunition can help prevent problems and improve the reliability of your shotgun. Avoid using cheap or poorly made ammunition, as this can cause malfunctions and damage your firearm.

Conclusion

The Mossberg 940 Pro Tactical is a fantastic shotgun, but like any firearm, it can sometimes experience problems. By understanding the common issues and following the troubleshooting tips outlined in this guide, you can keep your 940 Pro Tactical running smoothly and reliably. Remember to clean and lubricate your shotgun regularly, inspect it for any signs of damage or wear, and use high-quality ammunition. If you encounter a problem that you're not comfortable addressing yourself, don't hesitate to seek the help of a qualified gunsmith. Happy shooting, folks! With proper care and maintenance, your Mossberg 940 Pro Tactical will provide you with years of reliable service.