The world of firearms and ammunition demands precision. When dealing with calibers like the ubiquitous .556 NATO, ensuring proper chamber dimensions is paramount for safety and reliable function. This is where the .556 Go/No-Go gauge comes in – a critical tool for any serious firearms enthusiast, armorer, or gunsmith. This guide will delve into the intricacies of these gauges, explaining their function, importance, and how to use them correctly.
Understanding Go/No-Go Gauges: The Basics
Go/No-Go gauges are precision-machined tools used to check the dimensions of a firearm's chamber. They consist of two separate gauges:
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Go Gauge: This gauge is sized to the minimum acceptable dimensions of a .556 NATO chamber. If the Go gauge fits smoothly into the chamber, it indicates that the chamber is at least within the minimum acceptable size.
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No-Go Gauge: This gauge is sized to the maximum acceptable dimensions. If the No-Go gauge fits into the chamber, it indicates the chamber is at or beyond its maximum acceptable size. This is a significant issue requiring attention.
The critical difference lies in how these gauges interact with the chamber. The Go gauge should slide in easily, while the No-Go gauge should not enter the chamber or should encounter significant resistance. The smooth passage of the Go gauge and the resistance or inability to insert the No-Go gauge signify a chamber within the safe and functional tolerances.
Why are 556 Go/No-Go Gauges Essential?
Several reasons highlight the importance of using .556 Go/No-Go gauges:
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Safety: Improper chamber dimensions can lead to dangerous situations, such as:
- Bullet setback: A too-tight chamber can cause the bullet to be pushed back into the cartridge case, potentially leading to a squib load (a partially burned powder charge) or a catastrophic malfunction.
- Chambering issues: A too-loose chamber can lead to the round not properly seating, resulting in failure to fire or even a dangerous out-of-battery detonation.
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Accuracy: Chamber dimensions directly impact accuracy. A properly sized chamber ensures consistent and reliable bullet alignment, contributing to improved shot grouping.
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Troubleshooting: Go/No-Go gauges are invaluable for troubleshooting chamber issues. They allow for precise identification of problems, enabling timely repairs or replacement.
Using Your 556 Go/No-Go Gauges: A Step-by-Step Guide
Proper technique is crucial when using these gauges:
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Clean the Chamber: Ensure the firearm's chamber is clean and free of debris. Any obstruction can skew the results.
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Insert the Go Gauge: Carefully insert the Go gauge into the chamber. It should slide in smoothly and easily without resistance.
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Insert the No-Go Gauge: Attempt to insert the No-Go gauge. It should not enter the chamber easily, if at all. Significant resistance indicates the chamber is within acceptable limits. If it enters easily, you have a problem.
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Interpreting the Results: Smooth insertion of the Go gauge and resistance with the No-Go gauge confirm the chamber is within acceptable specifications. If the No-Go gauge fits easily, the chamber is oversized and requires attention from a qualified gunsmith.
Beyond the Basics: Considerations for Serious Users
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Gauge Material: Gauges are typically made from hardened steel to withstand repeated use.
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Regular Inspection: Regularly inspect your gauges for wear and tear. Damaged gauges can lead to inaccurate measurements.
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Professional Assistance: If you encounter any issues or are unsure about interpreting the results, consult a qualified gunsmith or armorer.
The .556 Go/No-Go gauge is a simple yet powerful tool that ensures the safe and reliable operation of your firearm. By understanding its function and using it correctly, you significantly enhance the safety and performance of your .556 NATO rifle. Remember that safety should always be your primary concern when handling firearms.
