How to Check Headspace on AR-15 Bolt: A Comprehensive Guide
Ensuring proper headspace on your AR-15 bolt is crucial for the reliability and accuracy of your firearm. Headspace refers to the distance between the bolt face and the breech face of the receiver when the bolt is fully closed. Incorrect headspace can lead to a variety of issues, including misfires, jams, and even catastrophic failures. In this guide, we will walk you through the process of checking headspace on your AR-15 bolt, providing you with the knowledge and tools needed to maintain your firearm’s performance.
Understanding Headspace
Before diving into the actual process of checking headspace, it’s important to understand what it is and why it matters. Headspace is the distance between the bolt face and the breech face of the receiver when the bolt is fully closed. This distance is critical because it ensures that the cartridge case is properly seated in the chamber and that the bullet is aligned with the rifling in the barrel. If the headspace is too tight, the cartridge may not fire properly. If it’s too loose, the bullet may not be properly aligned, leading to accuracy issues.
Tools Needed
Before you begin checking headspace, gather the following tools:
| Tool | Description |
|---|---|
| Caliper | Used to measure the bolt face and breech face. |
| Headspace Gauge | Used to measure the headspace between the bolt face and breech face. |
| Cartridge Case | Used to measure the headspace with the gauge. |
| Chamfering Tool | Used to chamfer the case mouth if necessary. |
Checking Bolt Face and Breech Face
Start by cleaning your AR-15 bolt and receiver thoroughly. Once clean, use a caliper to measure the bolt face and breech face. The bolt face should be measured at the widest point, and the breech face should be measured at the point where the bolt lugs meet the receiver. Record these measurements for later comparison.
Measuring Headspace
Now, it’s time to measure the headspace. Place the headspace gauge in the chamber of the receiver, ensuring that it is fully seated. Insert a cartridge case into the chamber, and then place the gauge over the case mouth. Push the gauge down until it contacts the bolt face. The gauge should be perpendicular to the bolt face. If the gauge is not perpendicular, adjust it until it is.
Once the gauge is in place, measure the distance between the gauge and the bolt face. This is the headspace measurement. Record this measurement and compare it to the factory specifications for your firearm. The specifications can typically be found in the owner’s manual or on the manufacturer’s website.
Interpreting the Results
Now that you have your headspace measurement, it’s time to interpret the results. If the headspace is within the factory specifications, your firearm is likely in good condition. However, if the headspace is outside the specifications, you may need to take further action.
If the headspace is too tight, you may need to chamfer the case mouth of your ammunition. This can be done using a chamfering tool or by carefully filing the case mouth. If the headspace is too loose, you may need to replace the bolt or have the receiver reamed to a larger diameter.
Conclusion
Checking headspace on your AR-15 bolt is an important maintenance task that can help ensure the reliability and accuracy of your firearm. By following this guide, you can measure and interpret your headspace, taking the necessary steps to keep your firearm in top condition. Remember, proper headspace is crucial for the safety and performance of your firearm, so don’t skip this important step.
