Gunsmithing AR Headspace

[BlueFalcorn]

Putting together an AR and had some questions about the headspace.

I checked the headspace (removing ejector and extractor) on a Aero Precision bolt/upper and a 12.5in Odin 223 wylde barrel (upper is assembled and barrel torqued to spec). The bolt assembly will fully close when inserted into the upper receiver with a Clymer 223 1.4666 no go gauge in the barrel. The bolt assembly will not fully close when inserted into the upper receiver with a Forster 1.4736 max head space gauge in the barrel.

Any input is welcome (have an email to the manufacturer, but don’t expect a response until next week)

 

[Ravenworks]

The bolt has to be disassembled for the gauge to work properly.

 

[BlueFalcorn]

I used the second method outlined in this video at Brownells. The ejector and extractor were removed from the bolt.

Is the 2nd method outlined in the video not legitimate?

 

[Rlandry]

This is why they make the field gauge. If the bolt locks with the no-go gauge but will not lock with the field gauge, you are marginal, but probably OK. If it closes on the field gauge, the gun needs to go to a smith or to the factory.
You need to use gauges all made by the same manufacturer.

 

[whatsupdoc]

223 chamber Datum is 1.4636 Min and 1.4736 Max so you should be fine.