The 5.56 NATO FIELD gauge, which is also known as the NATO MAX, is used to check the chamber headspace to determine when it should be taken out of service for repair. If the bolt closes on the Field Gage it is considered unsafe headspace and should be taken out of service for repair.
S**Y
I'm not expert but it seems to work!
I built an AR15 upper and wanted to make sure that the bolt and barrel (from different manufacturers) were playing nice with one another. I used this gauge to make sure that there wasn't a dangerously excessive amount of headspace and then used a live cartridge to make sure there was adequate headspace. The upper passed both 'tests' so I went and shot it. The upper didn't explode in my face so it would appear that this gauge works!
X**.
Five Stars
Like pic.
D**P
Five Stars
Thanks
Trustpilot
1 day ago
5 days ago
