Understanding the Cartridge and Headspace
Accuracy and safety are paramount when it comes to firearms. Whether you’re a seasoned shooter or just starting your journey into the world of firearms, the integrity of your weapon is something you should never take lightly. This is particularly true for the immensely popular AR-15 platform, chambered in the widely used 5.56x45mm NATO cartridge. This article dives into the essential topic of 5.56 Go/No-Go gauges, explaining their function and why they are absolutely crucial for maintaining a safe and dependable 5.56/.223 firearm.
Understanding and using 5.56 Go/No-Go gauges is fundamental for ensuring the safe and reliable operation of your 5.56/.223 firearm. We will explore why these simple tools play such a vital role in your gun maintenance routine.
The 5.56x45mm NATO Cartridge
The 5.56x45mm NATO cartridge is a standard intermediate cartridge used extensively by military forces and civilian shooters alike. It’s known for its relatively high velocity, flat trajectory, and suitability for a range of applications, from target shooting to self-defense. Its compact size and effective ballistics have made it the cornerstone of countless rifles, especially the AR-15.
The Importance of Headspace
At the heart of safe firearm operation lies the concept of “headspace.” Headspace refers to the precise distance between the bolt face and the portion of the chamber that stops the cartridge from entering further. Essentially, it’s the measurement that determines how far the cartridge can seat within the chamber. Proper headspace is absolutely critical because it directly affects how the firearm functions, how safely it operates, and even how accurate it can be.
The Risks of Incorrect Headspace
Incorrect headspace, whether too short or too long, can lead to a variety of dangerous situations. Too short a headspace can prevent the bolt from fully closing, leading to a failure to fire. More seriously, it can create excessive pressure when the cartridge is fired, potentially causing a catastrophic failure of the firearm. Too long a headspace can also contribute to failures to fire, but more significantly, it can lead to case separation during firing. A case separation can leave the front half of the casing stuck in the chamber. This can then lead to jamming and is difficult to clear, potentially causing further problems. It can also release high-pressure gases into the receiver, posing a serious danger to the shooter.
Headspace and the AR-15
The AR-15 rifle design utilizes a system where the bolt, barrel extension, and receiver interact to define the headspace. The barrel extension is a crucial component, containing the locking lugs that engage with the bolt to secure the cartridge within the chamber. The precise dimensions of the barrel extension, combined with the bolt’s design, determine the headspace. Maintaining the correct headspace is only possible if all of these parts work together harmoniously.
The Role of Go/No-Go Gauges
Go/No-Go gauges are specialized tools designed to accurately measure the headspace of a firearm. They’re a straightforward yet indispensable part of firearm maintenance. These gauges are precisely manufactured pieces of hardened steel, calibrated to specific dimensions that correspond to acceptable headspace limits.
Gauge Types
There are typically three primary types of gauges utilized in this process: the “Go” gauge, the “No-Go” gauge, and sometimes a “Field” gauge. These gauges work together to verify that the headspace of a firearm is safe and within acceptable parameters.
The “Go” Gauge
The “Go” gauge is manufactured to the minimum acceptable headspace dimension. If the bolt closes completely on the “Go” gauge, it means the headspace is long enough for the cartridge to seat correctly.
The “No-Go” Gauge
The “No-Go” gauge is manufactured to the maximum acceptable headspace dimension. If the bolt closes on a “No-Go” gauge, it indicates that the headspace is, at most, at the maximum limit of what is deemed to be safe and reliable. It’s a warning sign. It may be an indication of a problem, though it’s not always a critical issue.
The Field Gauge
A Field gauge is manufactured to a length that indicates the maximum safe headspace. If the bolt closes on a Field gauge, the headspace is *too long*, which means the firearm is unsafe to fire and requires immediate attention from a qualified gunsmith.
Gauge Construction
These gauges are constructed from durable materials, often hardened steel, to withstand the repeated use and pressures of the testing process. The precision manufacturing of these gauges is critical to ensure accuracy and to make sure that any measurements are reliable.
Why Employ Go/No-Go Gauges for Your 5.56/.223 Rifle?
The reasons to incorporate 5.56 Go/No-Go gauges into your regular gun maintenance are numerous, and they all contribute to a safer, more enjoyable, and more reliable shooting experience.
Safety First
Foremost is the safety factor. Gauges are critical in preventing potentially catastrophic failures. By ensuring the correct headspace, you dramatically reduce the risk of the firearm malfunctioning in a dangerous way. That means avoiding cases of a case head separation. This ensures that your AR-15 will not blow up in your face.
Reliability
Correct headspace is directly tied to reliability. If the headspace is within the proper range, the bolt will close completely, the cartridge will ignite, and the spent casing will extract smoothly. This ensures that the firearm cycles as intended, avoiding frustrating malfunctions that interrupt your shooting and are often caused by an improperly seated casing.
Potential for Improved Accuracy
While not the primary function of headspace measurement, proper headspace can also positively affect the accuracy of your rifle. Consistent and proper cartridge seating ensures that the bullet travels in the correct position down the bore of the barrel.
Peace of Mind
Knowing that your rifle is in good working order gives you peace of mind. It allows you to enjoy your time at the range without worrying about the potential for dangerous or unexpected events.
Legal Considerations
It’s crucial to remember that improper gun maintenance can lead to legal and liability issues. While most people don’t think of such things when cleaning their gun, it is important to maintain your firearms properly. A firearm owner has a responsibility to maintain their guns and ensure they are functional.
How to Use a 5.56 Go/No-Go Gauge
The process of using Go/No-Go gauges is straightforward, but it demands careful attention and adherence to safety protocols. *Always* treat every firearm as if it is loaded. Before you begin, ensure your work area is clean and well-lit.
Safety Precautions
Prior to testing, the firearm must be completely unloaded. Remove the magazine and carefully inspect the chamber to ensure it is empty. *Always* point the muzzle in a safe direction. This is not the time to be lackadaisical. Disassemble the rifle as needed to remove the bolt carrier group. For an AR-15, this means removing the upper receiver from the lower receiver and then removing the bolt carrier group from the upper receiver.
Cleaning the Chamber
Before inserting the gauges, clean the chamber and the bolt face thoroughly. Any debris or residue can affect the accuracy of the test.
Using the “Go” Gauge
Start with the “Go” gauge. Insert it into the chamber. You can hold the gauge in your fingers and insert the gauge. Then slowly close the bolt. You should be able to close the bolt gently. If the bolt closes completely and the locking lugs engage, the headspace is at least long enough to be within the minimum safe parameters.
Using the “No-Go” Gauge
Next, introduce the “No-Go” gauge. Insert the “No-Go” gauge into the chamber, taking care to keep the muzzle pointed in a safe direction. Close the bolt slowly. If the bolt *does not* close completely, the headspace is likely within acceptable limits. A little bit of resistance is often acceptable, but the bolt should not close fully.
Using the Field Gauge
If a “Field” gauge is included in the set, then after you’ve used the “Go” and “No-Go” gauges, you can use the Field gauge. Insert the Field gauge into the chamber. Close the bolt. If the bolt closes on the Field gauge, then the headspace is *too long*, and this is an unsafe condition.
Interpreting Results
If a gauge fails a test, you’ll need to carefully investigate the cause. The course of action for this can change.
Common Issues and Troubleshooting
Understanding the potential outcomes of your Go/No-Go gauge testing and how to troubleshoot them is critical. Here’s a breakdown of common scenarios:
Headspace Within Safe Limits
If the bolt *closes* on the “Go” gauge and *does not close* on the “No-Go” gauge, then your headspace is within a safe and acceptable range. In this case, the gun is safe to operate.
Headspace Too Short
If the bolt *fails to close* on the “Go” gauge, then the headspace is *too short*. This is a less common issue, but if it does occur, it indicates a potential problem with your barrel extension or bolt. Inspect the chamber and surrounding components. Check for any obstructions, such as debris or residue, that might be preventing the bolt from closing fully. If the problem persists, it is best to contact a qualified gunsmith.
Headspace Approaching Maximum
If the bolt *closes* on the “Go” gauge but also *closes* on the “No-Go” gauge, then the headspace is likely approaching the maximum acceptable limit. This is something to keep an eye on. It is possible to continue using the firearm. It’s wise to carefully examine the bolt, barrel extension, and other components for any signs of wear. Keep in mind that the gun is still considered safe, but it might be close to the maximum length.
Headspace Too Long
The most serious scenario arises when the bolt *closes* on the “Field” gauge. This signifies that the headspace is *too long*. This is a dangerous situation. You should immediately cease using the firearm. The rifle should be inspected by a gunsmith, who can determine the cause and make the necessary repairs or part replacements.
Other Potential Issues
Other factors that may impact the function and safety of your rifle include worn bolt lugs, a damaged barrel extension, and even an improper assembly of the firearm.
Seeking Professional Help
If you are uncertain about the cause of a headspace issue or are not comfortable performing repairs, consult a qualified gunsmith.
Choosing the Right Set
When it comes to selecting a 5.56 Go/No-Go gauge set, several factors come into play.
Material Quality
The gauge material is essential. The best gauges are constructed from hardened steel. This ensures both durability and accuracy, providing precise measurements over time.
Sourcing Gauges
Gauge sets are available from a wide variety of sources, from online retailers to brick-and-mortar gun stores. Be aware that the quality can vary from brand to brand, so choose your vendor wisely.
Researching Manufacturers
When choosing, research the reputation of the manufacturer. Reputable brands are known for producing accurate, reliable gauges. Check reviews and see what other firearm enthusiasts recommend.
Consider .223 Remington Compatibility
Also, when purchasing gauges, it is important to consider whether the set includes a .223 Remington gauge. While 5.56x45mm NATO and .223 Remington are often considered interchangeable, they have slight differences in their chamber dimensions, so a 5.56 gauge is preferable.
Regular Maintenance and Care
Proper storage of your gauges is important for their longevity and continued accuracy. After each use, clean them to remove any powder residue or debris. Store the gauges in a secure, dry location.
Checking for Damage
Check the gauges for any signs of damage. Over time, with repeated use, gauges can show signs of wear and tear. If a gauge is damaged, it will not provide accurate measurements, so you should replace it.
Frequency of Testing
When is it necessary to check headspace? It’s usually a good practice to check headspace whenever you install a new barrel, replace the bolt, or suspect a problem with your firearm. It’s also wise to test headspace whenever you purchase a new or used firearm. You should also conduct these tests periodically, depending on how frequently you use your rifle.
Conclusion
Using 5.56 Go/No-Go gauges is an essential step in the responsible ownership and maintenance of your 5.56/.223 firearm. These simple tools play a critical role in ensuring both the safety and reliability of your rifle. Regular testing ensures that your headspace is within the proper range. If there are any potential issues, then you can take action.
This article has provided a comprehensive overview of Go/No-Go gauges, how they work, and why they are essential. We have covered how to use the gauges, and we also covered troubleshooting potential problems that can arise. This allows you to make informed decisions about maintaining your firearm.
Remember, responsible firearm ownership includes not only proper training and safe handling practices, but also the ongoing maintenance of your equipment. By regularly checking the headspace of your firearm with Go/No-Go gauges, you are investing in your safety and that of others.
