Understanding AR-15 Bolt Headspace: A Comprehensive Guide

When it comes to the AR-15 rifle, the bolt headspace is a critical factor that can significantly impact the reliability and accuracy of the firearm. In this detailed guide, we will delve into what bolt headspace is, its importance, and how it affects your AR-15. Let’s get started.

What is Bolt Headspace?

Bolt headspace refers to the distance between the bolt face and the chamber of the firearm. It is a crucial dimension that ensures the correct fit of the cartridge case within the chamber. In the case of the AR-15, bolt headspace is typically measured in thousandths of an inch (0.001 inches) and is an essential factor in determining the firearm’s accuracy and reliability.

Why is Bolt Headspace Important?

Proper bolt headspace is essential for several reasons:

• Prevents chambering issues: If the bolt headspace is too tight, the cartridge case may not chamber properly, leading to feeding and extraction problems. Conversely, if the bolt headspace is too loose, the cartridge case may not be held securely, resulting in a potential for misfires or malfunctions.

• Ensures accuracy: Proper bolt headspace contributes to the overall accuracy of the firearm. When the cartridge case is held securely in the chamber, the bullet is more likely to be fired with consistent velocity, resulting in improved accuracy.

• Extends the lifespan of the firearm: A firearm with proper bolt headspace is less likely to experience malfunctions or wear and tear, leading to a longer lifespan.

Standard Bolt Headspace for AR-15

The standard bolt headspace for the AR-15 is typically 1.535 inches. This dimension ensures that the cartridge case is held securely in the chamber and allows for consistent feeding and extraction. However, it is essential to note that some custom firearms or barrels may require a different bolt headspace to achieve optimal performance.

Measuring Bolt Headspace

Measuring bolt headspace is a straightforward process. You will need a bolt headspace gauge, which is a specialized tool designed to measure the distance between the bolt face and the chamber. Here’s how to measure bolt headspace:

1. Remove the bolt from the firearm.

2. Insert the bolt headspace gauge into the chamber.

3. Secure the gauge in place and measure the distance between the bolt face and the gauge.

4. Compare the measurement to the standard bolt headspace for your firearm.

Adjusting Bolt Headspace

Adjusting bolt headspace is a task that should be performed by a qualified gunsmith. If the bolt headspace is too tight or too loose, the gunsmith can make the necessary adjustments by either resizing the chamber or using a different bolt. Here are some common methods for adjusting bolt headspace:

• Chamber resizing: This involves reducing the diameter of the chamber to achieve the desired bolt headspace.

• Bolt face resizing: This involves reducing the diameter of the bolt face to achieve the desired bolt headspace.

• Using a different bolt: Some firearms may require a different bolt with a specific bolt headspace to achieve optimal performance.

Table: Bolt Headspace Dimensions

Conclusion

In conclusion, bolt headspace is a critical factor in the performance of your AR-15 rifle. Ensuring proper