The 5.56x45mm NATO cartridge is a ubiquitous round in military and civilian applications worldwide. Ensuring the accuracy and safety of firearms chambered for this cartridge requires meticulous attention to detail, particularly when it comes to the dimensions of the chamber. This is where the 5.56 Go No-Go gauge comes in. This essential tool allows gunsmiths, armorers, and even serious hobbyists to verify that a firearm's chamber is within the specified tolerances. This guide provides a deep dive into the functionality, importance, and proper usage of a 5.56 Go No-Go gauge.
Understanding Go No-Go Gauges
Go No-Go gauges are precision-machined tools used to inspect the dimensions of firearm chambers. They consist of two distinct parts:
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Go Gauge: This gauge is designed to fit easily into a correctly dimensioned chamber. If the Go gauge does not fit easily, it indicates a problem with the chamber's dimensions.
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No-Go Gauge: This gauge is slightly larger than the Go gauge and is designed to not fit into a correctly dimensioned chamber. If the No-Go gauge does fit, it signals a significant problem that necessitates immediate attention.
The critical distinction lies in the subtle size difference between the two gauges. This difference represents the acceptable tolerance range for the chamber. A chamber that fails either the Go or No-Go test is considered out of specification and potentially unsafe.
Why is a 5.56 Go No-Go Gauge Important?
Using a 5.56 Go No-Go gauge is crucial for several reasons:
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Safety: A chamber that's too tight can cause excessive pressure, leading to catastrophic failures and potential injury. Conversely, a chamber that's too loose can result in erratic bullet flight, reduced accuracy, and potential malfunctions.
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Accuracy: A properly dimensioned chamber ensures consistent and accurate bullet performance. Out-of-spec chambers can contribute to significant variations in accuracy.
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Reliability: Proper chamber dimensions are essential for reliable cycling and feeding of ammunition. A poorly dimensioned chamber can lead to malfunctions such as stovepipes, failures to feed, and failures to eject.
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Legal Compliance: In many jurisdictions, regular inspection of firearms is required for legal compliance. Using a Go No-Go gauge demonstrates a commitment to safe and responsible firearms ownership.
How to Use a 5.56 Go No-Go Gauge
Using a 5.56 Go No-Go gauge requires care and precision:
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Clean the Chamber: Before using the gauge, ensure the firearm's chamber is thoroughly cleaned and free of debris. Any obstruction can skew the results.
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Insert the Go Gauge: Gently insert the Go gauge into the chamber. It should slide in smoothly and easily without any resistance.
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Insert the No-Go Gauge: Attempt to insert the No-Go gauge. It should not fit into the chamber. Even slight resistance indicates that the chamber is outside the acceptable tolerance.
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Interpret the Results: If the Go gauge fits easily and the No-Go gauge does not, the chamber is within specification. If either gauge fails to meet its respective criteria, the chamber needs professional attention.
What to Do if Your Chamber Fails the Test
If your chamber fails either the Go or No-Go test, do not attempt to use the firearm. Consult a qualified gunsmith or armorer for inspection and repair. Attempting to use a firearm with an out-of-spec chamber is extremely dangerous.
Conclusion
The 5.56 Go No-Go gauge is an indispensable tool for ensuring the safety and reliability of firearms chambered in 5.56x45mm NATO. Regular inspection with these gauges is crucial for maintaining safe and accurate firearm operation. Remember, prioritizing safety should always be paramount when handling firearms.
