Understanding the AR-15 Trigger Mechanism
The AR-15, an iconic firearm, stands as a testament to American ingenuity and a symbol of the right to bear arms. Whether used for recreational target shooting, competitive sports, or home defense, the reliability and functionality of an AR-15 are paramount. At the heart of this functionality lies the trigger mechanism. A properly functioning trigger is not merely a convenience; it’s a critical component for safe and accurate shooting. When the trigger fails to reset, however, it transforms a reliable tool into a potentially dangerous one. This article will delve into the common problem of an **AR trigger not resetting**, providing an in-depth analysis of its causes, effective troubleshooting steps, and practical solutions to restore your rifle’s functionality and ensure your safety.
The trigger group of an AR-15 operates as a precisely engineered system, crucial for controlling the firing process. Before addressing issues with the **AR trigger not resetting**, it’s crucial to understand the components and the sequence of events involved. This understanding forms the foundation for effective troubleshooting.
Let’s take a look at the key players in the AR-15 trigger group:
- **The Trigger:** This is the lever that the shooter pulls to initiate the firing sequence. It connects directly to the sear.
- **The Hammer:** The hammer is a spring-loaded component that strikes the firing pin to ignite the primer when released.
- **The Sear:** The sear holds the hammer in the cocked position until the trigger is pulled. When the trigger is pulled, the sear disengages, releasing the hammer.
- **The Disconnector:** The disconnector is a crucial safety feature. It catches the hammer if the trigger is not fully released after firing, preventing a slam-fire. This component ensures the hammer catches the sear before the bolt closes on the next round.
- **The Springs:** These springs, including the trigger spring and hammer spring, provide the necessary tension to keep the trigger and hammer in their correct positions and to ensure proper function.
In essence, when the trigger is pulled, it moves the sear, releasing the hammer. The hammer, powered by its spring, strikes the firing pin, which in turn ignites the primer, firing the round. Following this, the trigger, ideally, should reset, meaning the trigger moves back forward, allowing the sear to re-engage with the hammer as the bolt cycles and reloads the chamber, readying the rifle for the next shot. The entire process, from trigger pull to reset, is designed to be smooth and efficient.
However, if something goes wrong, the trigger may not reset, leading to a range of frustrating and potentially dangerous malfunctions. The problem of the **AR trigger not resetting** can stem from several underlying causes. Understanding these causes is the first step toward effective resolution.
Common Causes of AR Trigger Not Resetting
Problems with the trigger components themselves are a frequent culprit when facing an **AR trigger not resetting** situation:
Trigger Spring Challenges
A weak or broken trigger spring is a common cause. The trigger spring provides the necessary force to return the trigger forward after each shot. If the spring is worn, damaged, or improperly installed, it may not have sufficient strength to reset the trigger.
Hammer Spring Difficulties
Similarly, the hammer spring’s state also plays a vital role. The hammer spring’s responsibility is to drive the hammer forward. Issues like a weak or broken hammer spring can prevent the hammer from striking the firing pin with enough force to cycle the action correctly or, in extreme cases, can prevent it from resetting at all.
Sear Concerns
The sear is a precision-engineered part. If it becomes worn, damaged, or the engagement is incorrect, it may not properly engage with the hammer or disengage from the trigger. This can result in the hammer not cocking properly or the trigger not resetting.
Disconnector Difficulties
The disconnector is crucial for safety and functionality. Problems with the disconnector, such as not moving freely due to debris or being damaged, can lead to the hammer being captured by the disconnector prematurely, preventing reset.
Trigger/Hammer Pin Issues
These pins hold the trigger group components in place. If they are improperly installed, damaged, or if the wrong diameter pins are used, the trigger components might not function correctly, contributing to the **AR trigger not resetting** problem.
Aftermarket Trigger Troubles
While many aftermarket triggers offer enhanced performance, they can also introduce complications. Installation errors, using the wrong springs, incorrect lubrication, or design or manufacturing defects can all cause problems. Careful selection and professional installation, where needed, are important.
Beyond the immediate trigger components, external factors can also contribute to the frustrating experience of an **AR trigger not resetting**. These factors should not be overlooked during diagnosis:
Lubrication Considerations
Both over-lubrication and a lack of lubrication can cause issues. Too much lubricant can attract debris, leading to malfunctions. Insufficient lubrication can cause friction between components, which can hinder proper movement and reset.
Debris and Fouling
A dirty trigger group, filled with carbon buildup, brass shavings, or other debris, can restrict the movement of internal parts, thereby causing the **AR trigger not resetting** problem. Regular cleaning is essential.
Bolt Carrier Issues
The bolt carrier group (BCG) is responsible for cycling the action. If the bolt carrier does not move rearward far enough during the firing cycle, it might not allow the trigger to reset. This can be caused by buffer or spring issues, as well as a variety of other factors.
Ammunition Issues
Certain ammunition problems, like primers not being seated correctly or using faulty ammunition, can interfere with the trigger’s function.
Assembly Errors
Improper assembly of the trigger group, or even the entire lower receiver, can lead to malfunctions. Ensuring all components are correctly positioned and secured is a must.
Troubleshooting Steps
When you find that your **AR trigger not resetting**, you need a systematic approach to identifying and resolving the issue. Safety is paramount, so make sure your firearm is unloaded and pointed in a safe direction before starting any troubleshooting procedure.
The first step is a thorough visual inspection. Remove the upper receiver from the lower receiver. Inspect the trigger group for any visible signs of damage, such as broken parts, excessive wear, or obvious obstructions. Ensure all pins are securely in place. Check for any debris or dirt that may be hindering the movement of trigger components. Also, check for proper lubrication.
Next, conduct a functional check. With the upper receiver detached, cycle the charging handle. Does the trigger reset? If not, this indicates a problem within the lower receiver’s trigger group. If the trigger is resetting, the issue might be related to the upper receiver or the interaction between the upper and lower. If the hammer drops without the trigger being pulled (a condition known as “hammer follow”), immediately cease all activity with the firearm and have it examined by a qualified gunsmith.
After the visual and functional checks, it’s time to perform more focused testing and diagnosis. Identify the specific behavior of the malfunction to narrow down possible causes.
There are a few common failure modes associated with an **AR trigger not resetting**:
- **No Reset:** The trigger remains in the rearward position after firing, and the hammer does not re-engage.
- **Partial Reset:** The trigger moves forward slightly, but it does not fully reset.
- **Sporadic Reset:** The trigger resets sometimes but fails to reset at other times.
Once you understand the failure, start isolating the problem by methodically swapping components. You can try swapping out the trigger spring, hammer spring, or disconnector to see if the problem resolves. You can also try using a different ammunition. This will help you to identify which parts are contributing to the problem. If you have access to other AR-15 rifles, consider swapping complete trigger groups.
Solutions and Repair
Once you have pinpointed the cause of the **AR trigger not resetting**, the next step is finding a solution. The appropriate solution will vary depending on the source of the problem.
Often, the simplest solution is cleaning and lubrication. Disassemble the trigger group, clean all the components thoroughly using a suitable solvent, and then reassemble the trigger group, lubricating all the contact points with a quality gun lubricant. Ensure you are using the correct lubrication and not over-lubricating.
If cleaning and lubrication do not work, component replacement may be necessary. A damaged or worn spring, sear, disconnector, or other part will need to be replaced. Replacing components requires care and attention to detail. Choose quality replacement parts and ensure that they are compatible with your AR-15 model.
Carefully study instructions and diagrams, and use appropriate tools to remove and install the components. If you are unfamiliar with any aspect of the process, consult a qualified gunsmith.
In some cases, disassembly and reassembly might be required to fix an **AR trigger not resetting** problem. Ensure you understand the process thoroughly. Study diagrams, watch videos, and take your time. Improper assembly can lead to malfunctions and dangerous situations.
Some issues may be beyond the scope of the average user. A gunsmith with experience in AR-15 platforms can quickly diagnose complex problems, repair damage, and ensure the safety and reliability of your firearm. Don’t hesitate to seek professional help when necessary.
Aftermarket triggers can be an upgrade for your AR-15, but they also come with their own challenges. Always follow the manufacturer’s installation instructions carefully. If you experience issues with an aftermarket trigger, consult the manufacturer’s documentation or contact their customer support. It is possible to return the trigger to the manufacturer if any problems persist.
Preventing Future Issues
Preventing future instances of the **AR trigger not resetting** is crucial for maintaining the reliability and safety of your firearm. Regular maintenance is key. Establish a regular cleaning schedule, cleaning your rifle after each shooting session or at least after every few hundred rounds. Make sure to properly lubricate the trigger group components.
After each shooting session, inspect your trigger components for any wear or damage. Replace any worn or damaged parts promptly. The type of ammunition can also play a role. Using high-quality ammunition can help to prevent malfunctions.
Conclusion
In conclusion, the **AR trigger not resetting** is a common problem that can be frustrating and, more importantly, potentially dangerous. By understanding the trigger mechanism, the causes of the malfunction, and by following the troubleshooting steps outlined in this article, you can often diagnose and resolve the problem. Always prioritize safety, use quality components, and don’t hesitate to seek professional assistance when needed. Remember, proper trigger function is not merely a convenience; it is essential for safe and enjoyable shooting.
Take the time to learn about your rifle, understand the mechanics, and always prioritize firearm safety. Be sure to regularly maintain and inspect your AR-15. By doing so, you can keep your AR-15 operating at its best, ensuring reliability and safety for years to come.
