Technically there’s guages for.223 AND 5.56

As there is a difference.

All I’m addin* in this ticking time bomb of a thread..

And It goes like this...If you have to start a thread like this, instead of reading the millions of threads across google, and form your own conclusion then asking here won’t give you any feel good vibes.

You either check it and go or don’t and do things such as hart creek described along with watching, inspecting your fired brass, ejection pattern and more..

mustangfreek...thanks for posting this.

Well...you learn something new every day.

When I bought my gauges 30+ years ago from Brownells the .223 was all they offered, and I was told when I bought them from them (by them) that they were interchangeable.

After going to Forster's site it is showing that 5.56 headspace is up to .004 longer than a .223 "Field" gauge.

Now I feel bad because the barrels I rejected over the years for being able to close on a "Field" gauge were possibly/probably still in spec...

You can teach an old dog new tricks...

Regardless, headspace should still be checked by the CORRECT gauges.