Understanding the Foundations of Safe Chambering
Chambering Basics
The 7.62x39mm cartridge, a workhorse in the realm of firearms, enjoys widespread popularity and use. From the iconic AK-47 and its variants to a range of hunting rifles, this round has proven its versatility and effectiveness across diverse applications. Ensuring the safety and optimal performance of firearms chambered for this round demands meticulous attention to detail, and one crucial aspect of this is understanding and utilizing a Go No Go gauge.
Before delving into the specifics of the Go No Go gauge, it’s essential to grasp the fundamental principles of chambering and how they relate to the 7.62×39 cartridge. Proper chambering dictates the precise dimensions of the area within a firearm’s barrel where the cartridge rests before firing. When we speak of chamber dimensions, it’s all about ensuring the proper fit and function of the cartridge within the rifle. The chamber must be large enough to allow the cartridge to seat properly, but not so large that it compromises the bullet’s alignment or weakens the case during firing.
Headspace and Its Importance
One of the most critical measurements related to chambering is headspace. Headspace is the distance between the bolt face and a specific point on the chamber (typically the shoulder of the case). In the case of the 7.62×39, correct headspace is non-negotiable for safe operation. Too little headspace and the cartridge won’t chamber. Too much, and you run the risk of case head separation, a potentially catastrophic malfunction.
The consequences of improper chambering can range from minor inconveniences to severe safety hazards. A poorly chambered rifle might experience frequent failures to feed or extract spent casings. More seriously, excessive headspace can lead to the case head separating upon firing. This can release high-pressure gases backward, causing severe damage to the firearm and potentially injuring the shooter. Conversely, a chamber that’s too tight could lead to a misfire or, in extreme cases, a dangerous pressure spike.
The Role of a Go No Go Gauge
Defining the Tool
So, how does one ensure their 7.62×39 firearm has a properly dimensioned chamber? The answer lies, in large part, with the Go No Go gauge. This simple, yet effective tool provides a tangible method to verify the chamber’s critical measurements. But what precisely is a Go No Go gauge, and how does it work?
At its core, a Go No Go gauge is a precisely manufactured metal cylinder designed to mimic the dimensions of the 7.62×39 cartridge. A set of these gauges typically comprises a “Go” gauge and a “No Go” gauge, sometimes even a “Field” gauge. Each gauge serves a specific purpose in the chambering verification process.
How the Gauges Function
The Go gauge is designed to simulate the minimum allowable headspace for the 7.62×39 cartridge. If the bolt of the firearm closes completely on the Go gauge, it signifies that the chamber dimensions are within the acceptable minimum specifications. The No Go gauge, on the other hand, is slightly longer than the Go gauge. It represents the maximum allowable headspace. If the bolt closes on the No Go gauge, it indicates that the headspace is too great, potentially unsafe, and requires further investigation. The Field gauge is slightly longer than the No-Go gauge and serves as the maximum safe limit before the firearm is considered unsafe to use.
These gauges are usually crafted from high-quality, hardened steel to ensure longevity and accuracy. Precision manufacturing is paramount. Any deviation in the dimensions of the gauge could lead to an inaccurate assessment of the firearm’s chamber, potentially putting the shooter at risk.
Using the Go No Go Gauge: A Step-by-Step Guide
Safety First
Using a Go No Go gauge is a straightforward process, but it demands meticulousness and attention to detail. Always prioritize safety when working with firearms. Before you even think about reaching for the gauges, make sure the firearm is completely unloaded. Double-check the chamber and magazine to ensure there are no cartridges present. It’s always best to be sure of your surroundings and be free of distractions.
The Process
Once the firearm is confirmed to be unloaded, the following steps will guide you through the headspace verification process:
Begin by disassembling the bolt from your rifle. Clean the chamber thoroughly with a brush and solvent to remove any debris or oil that might interfere with the gauging process.
Insert the Go gauge into the chamber. Make sure the gauge seats fully.
Slowly and deliberately close the bolt on the gauge. This is an important step. If the bolt closes completely and smoothly, then the chamber is within minimum specifications. This is a good indication that the chamber is within acceptable limits.
Next, replace the Go gauge with the No Go gauge. This step is vital in verifying that the headspace isn’t too excessive.
Close the bolt again, employing the same smooth, deliberate motion. If the bolt closes completely on the No Go gauge, this indicates that the headspace is out of specification. It could be either too long or too short.
Interpreting the Results and Knowing What to Do
Understanding Outcomes
Understanding the results of these tests is crucial. Here’s a breakdown of what each outcome signifies:
If the bolt closes completely on the Go gauge and *doesn’t* close on the No Go gauge, this means your chamber is within acceptable headspace specifications. This is the optimal result. Your chamber is likely safe and the firearm can be safely fired with proper ammunition.
If the bolt closes on *both* the Go gauge *and* the No Go gauge, your chamber may be out of specification. Headspace may be too long or too short. If this is the case, immediately cease using the firearm and seek the assistance of a qualified gunsmith. This is a serious indication of a potential safety hazard.
If the bolt *doesn’t* close on either the Go gauge or the No Go gauge, there might be debris, or some other obstruction in the chamber. Re-clean the chamber thoroughly. If the problem persists, you should seek professional gunsmith help.
Common Issues and How to Troubleshoot
Troubleshooting Techniques
While the Go No Go gauge is generally a straightforward tool, certain problems may arise during the process. Being prepared for these issues can save time and frustration.
A common problem is the bolt failing to close smoothly on the gauge. This could be due to several reasons. The most common reason is the presence of debris or oil in the chamber or on the bolt face. Thoroughly cleaning both components is often the first step in resolving this issue. The next issue could be, and often is, from a new barrel build or a poor barrel fit. This is why it is so important to have a qualified gunsmith install a new barrel.
If the bolt still struggles to close, inspect the bolt lugs for damage or wear. Worn lugs can prevent proper locking, leading to an inaccurate headspace reading.
When the bolt refuses to close at all, or does so with excessive resistance, this might signal a problem. Inspect the chamber closely for any obstructions, such as a dented chamber or a piece of a stuck case.
Always remember to consult a gunsmith when you suspect a potential problem, or are uncertain about the results. Firearms are complex instruments, and attempting to address issues without adequate knowledge and experience can be dangerous.
Maintaining and Storing Your Gauges
Care and Storage Guidelines
Proper maintenance and storage of your Go No Go gauges are essential for maintaining their accuracy and extending their lifespan. These gauges are precision instruments, and treating them with care will ensure reliable headspace verification for years to come.
After each use, carefully clean the gauges with a suitable solvent to remove any powder residue, carbon deposits, or other contaminants. Use a soft cloth to avoid scratching the surface.
Store the gauges in a protective case or container. This will safeguard them from impacts, moisture, and other environmental factors that could lead to rust or damage. Keep the gauges away from any sources of heat or direct sunlight.
For added security, you can regularly check the accuracy of your gauges. Over time, even high-quality gauges can experience minor wear or damage. Periodic checks against known standards will provide confirmation of the gauges’ continued accuracy. Contact a reputable gunsmith to calibrate these.
Purchasing the Right Gauge Set
Choosing the Right Set
When purchasing a Go No Go gauge set for 7.62×39, you’ll find several options available. Always prioritize quality and accuracy. The best gauges are made from high-quality, hardened steel and are manufactured to precise tolerances.
Several reputable manufacturers specialize in producing these gauges. Seek out brands known for their commitment to accuracy and durability. Be sure to carefully review the specifications of each gauge set before making a purchase. The gauge set must be compatible with the 7.62×39 cartridge.
Also, you may want to check for SAAMI, or the Sporting Arms and Ammunition Manufacturers’ Institute gauges. This is the standard for ammunition production and should be used if you will be reloading.
Conclusion: Prioritizing Safety and Precision
The Go No Go gauge is an indispensable tool for anyone who owns or works with firearms chambered for the 7.62×39 cartridge. By understanding how these gauges work, following proper procedures, and prioritizing safety, shooters can gain confidence that the headspace of their rifles is within safe tolerances. Regular use of a Go No Go gauge, along with diligent maintenance, is a cornerstone of responsible gun ownership and safe firearm operation. It’s a small investment that can provide significant peace of mind and help you enjoy your shooting activities with greater confidence. The 7.62×39 cartridge is reliable, but safe firearms make it more enjoyable.
