Maintaining a properly functioning AR-15 requires diligent care and regular checks. Among the most crucial is verifying headspace and timing, critical factors impacting safety and reliability. This is where the go/no-go gauge comes into play. This comprehensive guide will explain what a go/no-go gauge is, how to use it, and why it's an essential tool for any serious AR-15 owner.
Understanding Headspace and Timing in Your AR-15
Before diving into the specifics of the gauge, let's understand the importance of headspace and timing.
Headspace: The Critical Cartridge-to-Bolt Gap
Headspace refers to the distance between the bolt face and the head of the cartridge when the bolt is fully closed. Incorrect headspace can lead to catastrophic malfunctions:
- Excessive headspace (too much space): This can cause a dangerous condition where the cartridge case can bulge or rupture, leading to potentially serious injury or damage to your firearm.
- Insufficient headspace (too little space): This can result in failure to fire or damage to the firing pin.
Timing: Ensuring Proper Bolt Alignment
Timing, on the other hand, refers to the alignment of the bolt lugs with the receiver's locking lugs. Improper timing can also cause malfunctions, including:
- Failure to lock: The bolt may not fully lock into the receiver, resulting in a potentially dangerous out-of-battery firing.
- Inconsistent cycling: The bolt may not cycle reliably, leading to malfunctions and jams.
Introducing the Go/No-Go Gauge: Your AR-15's Safety Net
The go/no-go gauge is a simple yet critical tool for checking both headspace and timing. It consists of two precisely machined gauges:
- Go Gauge: This gauge represents the maximum acceptable headspace. If the go gauge fits smoothly and easily, it indicates that your headspace is within the acceptable range.
- No-Go Gauge: This gauge represents the minimum unacceptable headspace. If the no-go gauge fits, it indicates that your headspace is excessive and requires immediate attention. The no-go gauge should NEVER fit.
Using these gauges together provides a clear and safe way to verify headspace and timing.
How to Use a Go/No-Go Gauge for Your AR-15
Using a go/no-go gauge is straightforward, but precision is key:
- Safety First: Always ensure your firearm is unloaded and clear of ammunition. Double-check!
- Insert the Go Gauge: Insert the go gauge into the chamber, mimicking the insertion of a cartridge. It should slide in smoothly and easily. If it doesn't, there may be an obstruction in the chamber.
- Close the Bolt: Close the bolt completely. The go gauge should fit snugly, but smoothly.
- Remove the Go Gauge: Carefully remove the go gauge.
- Insert the No-Go Gauge: Now, insert the no-go gauge. It should NOT fit. If the no-go gauge fits, your headspace is excessive, and you must not fire the weapon until the problem is rectified by a qualified gunsmith.
- Visual Inspection: While the gauges primarily check headspace, visually inspect the gauges for any signs of damage or misalignment to ensure the integrity of the process.
Importance of Professional Help
While using a go/no-go gauge is relatively simple, interpreting the results and addressing any issues requires expertise. If your no-go gauge fits, or if you have any doubts about your results, immediately consult a qualified gunsmith. Attempting to repair or adjust headspace yourself can be dangerous and may permanently damage your firearm.
Conclusion: Prioritize Safety with Regular Checks
Regularly checking your AR-15's headspace and timing with a go/no-go gauge is an essential part of responsible gun ownership. This simple procedure can prevent potentially catastrophic malfunctions and ensure the safety and reliability of your firearm. Remember, safety should always be your top priority. Invest in a quality go/no-go gauge and use it regularly. Your safety depends on it.
