The 5.56 NATO cartridge is a ubiquitous round in military and civilian applications. Ensuring the proper functioning of firearms chambered in this caliber is critical for safety and reliability. One essential tool for this is the go/no-go gauge 5.56, a simple yet vital device used to inspect the headspace of a firearm's chamber. This guide delves into the specifics of 5.56 go/no-go gauges, their use, and importance.
Understanding Go/No-Go Gauges
A go/no-go gauge is a precision-machined tool consisting of two separate gauges:
-
Go Gauge: This gauge is sized to the exact specifications of a correctly dimensioned chamber. It should smoothly and easily enter the chamber. If it doesn't, this may signal a problem.
-
No-Go Gauge: This gauge is slightly larger than the go gauge, representing the maximum acceptable headspace dimension. It should not enter the chamber. If it does, it indicates excessive headspace, a serious safety issue.
This simple system allows even untrained individuals to quickly and easily assess the headspace of their firearm's chamber. Incorrect headspace can lead to catastrophic malfunctions, including squib loads (incomplete powder burn), primer failures, or even chamber explosions.
Why 5.56 Go/No-Go Gauges Are Essential
The 5.56x45mm NATO cartridge has specific dimensional tolerances. Over time, wear and tear on the firearm's chamber can cause the headspace to increase. Headspace is the distance between the bolt face and the breech face of the chamber. Excessive headspace compromises the safety and reliability of the firearm.
-
Safety: Excessive headspace can lead to a dangerous condition where the cartridge case expands too far into the chamber upon firing. This can cause the cartridge case to rupture, resulting in injuries or damage to the firearm.
-
Reliability: Incorrect headspace can lead to inconsistent ignition, feeding, and extraction problems. This renders the firearm unreliable and potentially dangerous.
-
Accuracy: Though less immediate than safety concerns, excessive headspace can negatively impact the accuracy of the firearm.
Using a 5.56 Go/No-Go Gauge
The process of using a go/no-go gauge is straightforward but requires careful attention to detail:
-
Clean the chamber: Thoroughly clean the firearm's chamber to ensure accurate measurement. Any debris can interfere with the gauge's proper functioning.
-
Insert the Go Gauge: Gently insert the go gauge into the chamber. It should slide in smoothly without force. If it encounters resistance, this is a potential problem.
-
Insert the No-Go Gauge: Attempt to insert the no-go gauge. It should not enter the chamber. If it does, this clearly indicates excessive headspace.
-
Interpret the Results: If both gauges function correctly (go gauge passes, no-go gauge fails), the headspace is within acceptable parameters. If the no-go gauge passes, immediate action is required. The firearm needs to be inspected by a qualified gunsmith.
Case Study: Headspace Issues in a 5.56 AR-15
A common issue with AR-15 rifles is the potential for headspace problems, particularly with excessive wear and tear on the bolt and barrel. A hypothetical case study: A user experiences multiple misfires and inconsistent cycling in their AR-15. Upon inspection with a 5.56 go/no-go gauge, they find that the no-go gauge enters the chamber. This confirms that the headspace is too large. This situation necessitates a professional assessment and potential replacement or repair of the bolt or barrel.
Where to Purchase Go/No-Go Gauges
Reputable sources for 5.56 go/no-go gauges include:
- Specialized Gunsmithing Supply Companies: These often carry a wider range of gauges and other firearm maintenance tools.
- Online Retailers: Major online retailers that specialize in firearms and accessories may sell go/no-go gauges.
- Local Gun Stores: Your local gun store is likely to carry go/no-go gauges or be able to direct you to a supplier.
Always ensure that the gauge is certified to the correct 5.56 NATO specifications.
Conclusion: The Importance of Regular Inspection
Regular inspection using a 5.56 go/no-go gauge is a vital part of responsible firearm ownership. It's a simple yet effective way to ensure the safety and reliability of your firearm. The small investment in a gauge can save you from much larger expenses – or worse – down the road. Ignoring potential headspace problems can be dangerous. Always prioritize safety and follow best practices for firearm maintenance.