Introduction
The world of firearms ownership is built on a foundation of responsibility, safety, and a deep understanding of the mechanisms involved. One of the most critical aspects of maintaining a rifle and ensuring its safe operation is understanding and properly checking its headspace. Far beyond mere routine maintenance, understanding headspace is fundamental to preventing potentially catastrophic failures and ensuring the longevity of your firearm. This article serves as a comprehensive guide, breaking down the process of checking headspace on a rifle, emphasizing safety, and highlighting the importance of expert assistance when necessary.
Headspace, in its simplest terms, refers to the distance between the bolt face of a rifle and the point in the chamber where the cartridge case stops. This measurement is absolutely critical because it dictates how the cartridge seats within the chamber during firing. Precise headspace ensures proper cartridge alignment, reliable ignition, and prevents dangerous overpressure situations that can cause serious harm to the shooter and damage to the firearm. Incorrect headspace, whether too short or too long, can lead to a variety of dangerous malfunctions, including case ruptures and potentially severe injuries.
Checking headspace isn’t something you do every time you handle your rifle, but it is a vital check under certain circumstances. Consider this check essential after a barrel change, a common modification among rifle enthusiasts. Every barrel has slightly different dimensions, and the headspace needs to be confirmed after installation. Buying a used rifle also warrants a headspace check. You don’t know the history of the rifle and the possibility of wear, alteration, or previous issues. If you experience any malfunctions such as difficult bolt closure, extraction problems, or visible signs of case damage, a headspace check should be one of the first diagnostic steps. This preventative measure helps diagnose and fix problems before they become serious.
Safety Precautions – MUST BE EMPHASIZED
Before delving into the how-to guide, it’s paramount to emphasize the cornerstone of any firearm activity: **SAFETY**. A gun is a powerful tool, and its misuse can have severe consequences. Always ensure the firearm is unloaded. Verify this by visually inspecting both the chamber and the magazine well (if applicable) to confirm no ammunition is present. Point the muzzle in a safe direction, ideally toward a designated backstop or a direction where a negligent discharge would cause minimal harm.
Wear appropriate eye protection, like safety glasses, to shield your eyes from potential debris. Ear protection, like earmuffs or earplugs, is also crucial because, even during this process, loud noises can occur if the bolt is slammed or if a gauge gets stuck. If at any point you’re unsure about a step, or if you encounter unexpected resistance, stop immediately and consult with a qualified gunsmith. Your safety and the integrity of the firearm are the top priorities. When in doubt, always seek professional guidance.
Tools and Materials Needed
Checking headspace requires specialized tools designed for precision. These are called headspace gauges. They are essentially precision-machined metal cylinders made to the exact dimensions that are required for the cartridge. There are several types of headspace gauges, each serving a specific purpose in the verification process. The most common types are the “Go,” the “No-Go,” and the “Field” gauges. Each of these gauges provides a different measurement that helps determine the condition of your rifle’s headspace.
The “Go” gauge is manufactured to the minimum allowable headspace for a specific cartridge. The bolt should close completely and lock on this gauge. If the bolt closes and locks on the “Go” gauge, it indicates that the headspace is at least within the minimum acceptable specifications, but does not guarantee that there is no excessive headspace.
The “No-Go” gauge is made slightly longer than the “Go” gauge, and represents the maximum allowable headspace. The bolt should not close completely and lock on this gauge. If the bolt closes and locks on the “No-Go” gauge, it indicates that the headspace is too long. If the bolt closes on the “No-Go” gauge, it indicates that the headspace is too long and the rifle may be unsafe to fire.
The “Field” gauge, also known as a “reject” gauge, is the longest of the three and represents a dimension at which the rifle would be dangerous to shoot. As a final test of safety, the rifle should not close on this gauge.
Besides the headspace gauges, other tools can be helpful. These might include a cleaning rod with a bore brush or patch holder, cleaning solvent to remove any residue from the chamber, and a flashlight or bore light to examine the chamber. If, by chance, a gauge gets stuck, a soft-faced hammer or mallet might be used, with extreme caution, to gently tap the bolt open.
Step-by-Step Guide to Checking Headspace
Now, let’s walk through the practical steps of checking headspace. This is a task that, if performed correctly, can provide a high degree of confidence in the firearm’s safe functionality.
Before starting, make sure that the rifle is completely unloaded and the chamber is clear. Disassemble the bolt from the rifle’s receiver following the manufacturer’s instructions. In most cases, this is accomplished by manipulating the bolt handle and extracting the bolt from the receiver. This may involve removing the bolt from the rifle, depending on the rifle’s design, allowing full access to the chamber for the gauges. Using a bore brush and cleaning solvent, meticulously clean the chamber. Remove any oil, debris, or residue that may interfere with the accurate measurement. A clean chamber is essential for a reliable and precise test.
Using the “Go” Gauge
Begin by using the “Go” gauge. Insert the “Go” gauge fully into the chamber. Gently close the bolt, as you would when loading a cartridge. With the bolt closed, carefully attempt to lock it. If the bolt closes and locks completely on the “Go” gauge, this is the initial positive indication. If the bolt does not close completely, the headspace is likely too short. If the bolt fails to close on the “Go” gauge, it often indicates there’s a problem like a burr in the chamber.
Using the “No-Go” Gauge
Next, use the “No-Go” gauge. Remove the “Go” gauge and insert the “No-Go” gauge into the chamber. Again, close the bolt gently as if you were closing on a live round. Observe how the bolt functions. Ideally, the bolt should *not* close completely and lock. It should stop short of completely locking. If the bolt closes and locks on the “No-Go” gauge, it indicates excessive headspace. If the bolt does close on the “No-Go” gauge, the rifle could be potentially dangerous to fire.
Using the “Field” Gauge
If you have a “Field” gauge, this is the final test. Remove the “No-Go” gauge, and then insert the “Field” gauge into the chamber. Try to close the bolt. As with the “No-Go” gauge, the bolt should not close completely. If the bolt closes and locks on the “Field” gauge, the rifle is considered to have excessive headspace and should never be fired.
Troubleshooting and Interpretation
If the bolt closes on the “No-Go” or the “Field” gauge, the headspace is likely too long, a potentially dangerous situation. Do not fire the rifle! The excessive headspace can lead to a case rupture upon firing, potentially causing serious injury. If the bolt doesn’t close on the “Go” gauge, the headspace is too short, and the chamber may be too tight, or other problems may exist. In either of these scenarios, you’ll need the expertise of a gunsmith to diagnose and rectify the issue.
Interpreting these results is paramount. When the bolt closes on the “No-Go” or “Field” gauge, it signifies that the headspace is too long. This can result from several issues, including excessive wear on the barrel or receiver, improper barrel installation, or damage to the bolt. Firing a rifle with excessive headspace can cause the cartridge case to stretch excessively during firing, ultimately leading to case rupture. This rapid expansion of gases could cause injury.
If the bolt closes and locks on the “Go” gauge but fails to close on the “No-Go” gauge, the headspace is within acceptable limits. This doesn’t guarantee that your rifle is perfect, but it does mean that headspace is likely safe for use.
The headspace check process is a vital part of responsible firearm ownership. However, it’s essential to recognize your limitations. Attempting repairs beyond your skill level can jeopardize your safety and the integrity of the firearm. If you’re uncertain about any step or discover an issue with the headspace measurement, it is always best to seek professional assistance from a qualified gunsmith.
What to Do If Headspace is Incorrect
Should the headspace prove to be incorrect, never attempt any modification yourself unless you are a qualified gunsmith. Correcting headspace often requires specialized knowledge and equipment. A gunsmith will be able to accurately diagnose the issue, determine the best course of action, and perform the necessary repairs safely. This might involve replacing the barrel or modifying the bolt face. Do not attempt to resize a chamber yourself as it requires the correct tools, and expertise.
Frequently Asked Questions (FAQ)
How often should I check headspace?
As mentioned earlier, it’s not a daily ritual. Check headspace after any barrel work, when buying a used rifle, or if you suspect a problem, such as extraction issues or case damage. Regularly inspecting your rifle for signs of wear and tear is always recommended.
Can I check headspace without the correct tools?
No, you can’t reliably and safely check headspace without proper headspace gauges. Improvised methods are dangerous and can give you incorrect results.
What causes headspace to change?
Wear and tear over time, especially from firing thousands of rounds, can cause slight changes in headspace. Incorrect barrel installation or the use of incorrect ammunition can also affect headspace.
What are the signs of excessive headspace?
Extraction problems, bulged or split cartridge cases, and difficult bolt closure are common indicators of excessive headspace.
Conclusion
Checking headspace is a crucial skill for any responsible rifle owner. It provides peace of mind and acts as a shield against potentially dangerous situations. This understanding ensures your rifle is functioning properly.
Remember, always prioritize safety. Treat every firearm as if it were loaded, and never point it at anything you aren’t willing to destroy.
This article has provided you with an overview of how to check headspace on a rifle. The information provided here is for informational purposes only. Always seek guidance from a qualified gunsmith for any repairs or modifications to your firearms. The author/website is not responsible for any harm arising from improper use of the information presented.
