Understanding the Essence of Headspace
What is Headspace?
Before we delve into the specifics of Go No Go gauges, it’s critical to grasp the very core of headspace. Think of it as the precise distance between the bolt face and the point in the chamber where the cartridge stops. It’s not just a measurement; it’s the guardian of safe and accurate shooting.
This seemingly simple measurement dictates how a cartridge sits within the chamber when the bolt is closed. A correct headspace ensures that the cartridge is properly supported, allowing the firing pin to strike the primer with the necessary force to ignite the propellant. It prevents dangerous situations, such as the cartridge being too short or too long for the chamber.
Imagine a scenario where the headspace is excessive. The cartridge case can stretch too far upon firing, potentially leading to case head separation. This, in turn, could cause a sudden release of high-pressure gases, damaging the firearm and posing a serious risk of injury to the shooter and those nearby. Conversely, too little headspace might make it difficult or impossible to chamber a round, and could potentially lead to a dangerous overpressure situation if a round is forced in.
Headspace is therefore intertwined with chamber dimensions. The chamber, meticulously carved into the rifle’s barrel, is designed to accommodate the specific cartridge dimensions of the .308. The correct headspace ensures that the bullet aligns precisely with the rifling, maximizing accuracy. A mismatched chamber, or one that has been altered by use or improper maintenance, may render the firearm unsafe.
The Perils of Incorrect Headspace
The consequences of incorrect headspace can range from minor inconveniences to life-threatening disasters. It is more than just a technicality. An improper headspace can manifest itself in several ways, each posing a potential risk to the user and to anyone in the vicinity.
A common problem is the failure to fire. This is when the cartridge is not seated correctly, leaving the firing pin unable to reach the primer. While frustrating, it is often less hazardous than other problems.
Extracting fired cases can also be difficult if the headspace is incorrect. The case might expand excessively and become stuck in the chamber, requiring significant force to remove. This disrupts the shooting process.
More severely, excessive headspace can lead to case rupture or case head separation. The rear of the cartridge case, near the rim, may fail upon firing, resulting in the uncontrolled release of hot, high-pressure gases. These gases can cause significant damage to the firearm, including the bolt and receiver, and are a significant risk to the shooter, as they are directed toward the shooter’s face.
Catastrophic firearm failure is the worst-case scenario. This involves a complete structural breakdown of the firearm. This can be due to a variety of factors, including severely excessive headspace. Parts can shatter, fragments can be ejected at high velocity, and the entire event can be extraordinarily dangerous.
The Key Role of .308 Go No Go Gauges
While other methods of measuring headspace exist, they are often complex and impractical for the average shooter. The .308 Go No Go gauges provide a simple, reliable, and readily accessible way to measure headspace. They act as standardized reference tools to ensure the chamber dimensions of your .308 rifle are within the specified tolerances for safe and effective use.
These gauges are typically precision-machined tools. They are made from hardened steel. The hardened steel is designed to withstand repeated use. These gauges are crucial components in any conscientious firearm owner’s toolkit.
Exploring Different Types of .308 Go No Go Gauges
Understanding the different gauges and their purposes is vital for proper use. There are several different types of gauges for measuring headspace.
The Go gauge is the shorter gauge. Its purpose is to verify that the chamber is long enough. It is a critical “minimum” measurement. If the bolt closes easily on the Go gauge, it indicates that the chamber is within the acceptable minimum headspace.
The No-Go gauge is the longer gauge. This gauge is designed to test the maximum safe headspace. If the bolt closes on the No-Go gauge, it suggests that the headspace is too long, and the chamber is likely outside the manufacturer’s specifications. This indicates a problem, and the firearm should be inspected by a qualified gunsmith.
Field gauges are even longer than No-Go gauges. These gauges represent the absolute maximum acceptable headspace. Using a field gauge means the chamber is considered safe to use, but at its maximum tolerance.
How to Put .308 Go No Go Gauges to Work: A Step-by-Step Approach
Using .308 Go No Go gauges is a straightforward process, but it must be approached with the utmost attention to safety and detail. Correctly applying these tools requires precision and adherence to proper procedure.
Before you begin, the single most important consideration is safety. Always ensure the firearm is unloaded, with the magazine removed. Inspect the chamber visually and physically to confirm the absence of any cartridges. Point the muzzle in a safe direction throughout the process. All firearm safety rules apply.
The environment should be well-lit and free from distractions. Have a clean, stable workspace to prevent mishaps.
The first step involves cleaning the chamber and bolt face. Any debris, oil, or residue can interfere with the accuracy of the gauge readings. You should remove the bolt from the firearm.
Next, you will introduce the Go gauge. Insert the Go gauge into the chamber. Slowly close the bolt. The bolt should close completely without excessive force or resistance. The bolt should go into battery easily, with no apparent interference.
The second gauge to test is the No-Go gauge. Insert the No-Go gauge into the chamber. Close the bolt as you did with the Go gauge. The bolt should resist closing. Do not force it. The bolt should typically not close completely on the No-Go gauge. If it does, it suggests a problem with the headspace.
(If using a Field gauge) Perform the same procedure as the No-Go gauge test. Check if the bolt closes on the Field gauge. The bolt closing on the Field gauge indicates the chamber is at the maximum headspace. The firearm is considered safe to use but requires careful monitoring and inspection.
It’s imperative to document the results. Keep a record of which gauges the bolt closed on, and when. This is vital for monitoring the headspace of the firearm over time.
Understanding the results of the tests is crucial.
- Go gauge only: The headspace is within the minimum and maximum acceptable limits. The firearm is considered safe and is working correctly.
- Go and No-Go gauges: The headspace is too long and the firearm should not be fired until it has been inspected by a qualified gunsmith.
- Go, No-Go, and Field gauges: While the rifle may still function safely, the headspace is at the maximum acceptable limit and requires close monitoring.
Addressing Potential Difficulties and Common Issues
The process of using .308 Go No Go gauges is not always perfect. Recognizing and addressing some of the potential issues is important for safe and accurate use.
If the bolt does not close on the Go gauge, the chamber might be undersized or obstructed. This could be caused by a burr, debris, or a problem with the chamber itself. Cleaning the chamber and bolt face is the first step. If the bolt still does not close, take the firearm to a gunsmith for further inspection.
If the bolt closes on the No-Go gauge, it suggests that the headspace is too long. The firearm is not safe to fire and requires professional attention. It could be a problem with the bolt, the receiver, or the barrel, each requiring a skilled assessment.
Proper cleaning and maintenance play a critical role. Keeping your firearm clean and well-maintained is essential for accurate headspace readings. A dirty chamber, or bolt face, can introduce inconsistencies.
Why These Gauges Matter: Beyond mere Safety Considerations
While ensuring safety is the paramount reason for using these gauges, their significance extends well beyond. The gauges influence both accuracy and the lifespan of your firearm.
Proper headspace impacts the accuracy of your shots. Consistent and accurate headspace leads to consistent bullet seating and ignition. This, in turn, contributes to tighter groupings. An improperly headspaced cartridge could lead to an inconsistent flight path and degrade accuracy.
Excessive headspace can accelerate wear and tear on the firearm. The stresses placed on the components during firing are amplified when the cartridge is not properly supported. This can shorten the barrel life.
The correct headspace is also important for handloading. When reloading ammunition, you will work with cases that have been fired in your specific rifle. Proper headspace allows reloaders to make small adjustments to their handloads, optimizing their performance.
In Conclusion: A Tool of Prudence
The .308 Go No Go gauges are an invaluable asset for anyone who owns or works with a .308 rifle. They play a crucial role in ensuring safety and maximizing accuracy.
Using these gauges, following the procedures outlined above, gives you a way to perform routine checks on the headspace of your .308 rifle. These checks are crucial. They provide the information to ensure the firearm’s safe operation and longevity.
Remember to practice safe gun handling at all times. If you are unsure about any step in the process, consult a qualified gunsmith. They can provide you with the necessary assistance and guidance.
The use of these gauges is a sign of prudent and responsible ownership.
