.223 case guage

[redw7blue]

Why can I take once fired brass which has not been resized and it fits fine into my dillon case gauge?

There really is no difference between the once fired brass, once fired brass resized and the brass I bought from top brass I have.

All three fit just fine into my case gauge.

I would have thought that the once fired unresized brass would not fit into the case gauge.

 

[Slamfire]

I have Wilson gages. But from your description, seems Dillon cuts their gages the same as Wilson.

A Wilson gage only measures length. They do not measure "fatness", unless the case is grossly over width.

Wilson (and I guess Dillon) can buy reamers cut to whatever dimensions they want. So they bought reamers that allow the length of the case to be measured, even if the case has been fired.

You can get a pretty accurate measurement of your rifle chamber headspace by dropping a fired case into a Wilson gage and measuring up from the Go line.

 

[kelbro]

Maybe you have a nice chamber...

 

[243winxb]

http://www.thehighroad.org/showthread.php?p=5156525 Thread on the subject. My brass gets shorter on firing(head to shoulder). Must be the fat 5.56 chamber. The case gets .005" larger (body diameter) after firing right behind the shoulder when measured with a micrometer. Still fits the loose wilson gage.