View Full Version : 5.56 headspace gauge

08-14-2010, 7:18 AM
Is this the correct tool to use on a used AR15 bolt and a 5.56 chambered barrel? Brownells part no. 319-418-033 (Colt 5.56 Headspace Gauge).

08-14-2010, 7:52 AM
It looks like it but have you done either; (brownells) seen extensive service or have been rebarreled. If you are just assembling the gun you wont need it. The person that fits the extention to the barrel would need the tool.

08-14-2010, 8:06 PM
I have several bolts from years back that I want to find out which one is still good or not for a cheap plinker I'm building for my brother in law.

08-14-2010, 9:48 PM
theoretically they should all work, but it's never a bad idea to check.

the gauge you linked to will verify maximum safe headspace. you may also want to get a go gauge to check minimum.