Here is the thread from a previous post about headspace gages.
Headspace gauges in 5.56mm: bolt dissassembly?

I cannot find rebated rim 5.56mm GO and NO GO gages, anywhere on the Internet.  

I want to experiment with making a rebated rim 5.56mm GO and NO GO gages, so that headspace can be checked without having to disassemble the bolt, like the USGI FIELD gage allows.  I need a machinist who can put these gages in a lathe to rebate the rim.

I can include an extra GO and NO GO 5.56mm gages for the work involved.

I am thinking of one of the following gages from Brownells.  I prefer the Forster (bottom photo), because dealer cost is half as much as the Clymer.  Brownells does not show a dealer discount for Clymer.  I use Forster for my Garand and M1A builds without issue.




If anyone is interested in this, let me know.  

A go gauge with a rebated rim may cause false readings. The bolt face may not be flat or perpendicular to the chamber. I have a bolt now that the face is two different levels across it.

Why the need for the extra gages, when all the military uses is the field?

Military uses GO and NO GO gages, though not as extensively as the FIELD gage.

imo the field gauge would get you by but the others would make sure of it.






but if you really wanted to do it i would either contact steve@adcofirearms or the mad machinist mongo

The military uses guages with rebated rims.  I'm sure there are some floating around for sale.

Quoted: The military uses guages with rebated rims.  I'm sure there are some floating around for sale.

think youre referring to the field gauges

The way I go it is that there is only a USGI field gauge because that is all the military needs. The military is not in the business of building firearms so they don't need GO/NO-GO gauges.

It is in the works.  I will post when done.