Brownells Tech Tip: AR-15 Headspace

Published on March 17, 2015
Duration: 4:15

This guide details the essential AR-15 headspace check procedure, as demonstrated by a Brownells Tech Expert. It covers stripping the bolt, using Go and No-Go gauges to ensure proper chamber depth, and checking headspace on both stripped components and a fully assembled upper. Proper headspace is critical for safe and reliable firearm function, preventing issues like case separation.

Quick Summary

Checking AR-15 headspace is vital for safety and function. Use Go and No-Go gauges after stripping the bolt (removing extractor/ejector) to ensure the chamber isn't too short or too long. The bolt should close on a Go gauge but not a No-Go gauge, preventing issues like case separation.

Chapters

  1. 00:00Intro to AR-15 Headspace
  2. 00:17When to Check Headspace
  3. 00:44Bolt Preparation Steps
  4. 01:04Go Gauge Test Procedure
  5. 01:38No-Go Gauge Test Procedure
  6. 02:03Assembled Rifle Headspace Check
  7. 02:58Military Specs & Safety Risks

Frequently Asked Questions

What are Go and No-Go gauges for an AR-15?

Go gauges ensure your AR-15 chamber is deep enough for safe firing, while No-Go gauges prevent the chamber from being dangerously deep. Both are critical for safe and reliable operation, especially after parts replacement or new builds.

When should I check the headspace on my AR-15?

You should check AR-15 headspace when building a new rifle, replacing the barrel or bolt, or when evaluating a used firearm. This ensures the firearm operates safely and prevents potential malfunctions or damage.

What happens if my AR-15 has excessive headspace?

Excessive headspace in an AR-15 can lead to dangerous conditions like case head separation, where the base of the cartridge detaches upon firing. This can cause malfunctions and potentially damage the firearm or injure the shooter.

How do I check headspace on an assembled AR-15 upper?

To check headspace on an assembled AR-15 upper, insert the appropriate Go or No-Go gauge into the chamber. Then, push the bolt carrier group firmly into battery. The bolt should close on the Go gauge but not on the No-Go gauge.

Related News

All News →

More Gunsmithing & DIY Videos You Might Like

More from Brownells, Inc.

View all →