Testing some pex crimps before I do the actual water lines.

What is the correct way to test with the gauge ?

Should the gauge rotate around the crimp freely/evenly ?

Some I've tried seem to fit but when rotated it wants to pull away or leave a small gap.

Any advice appreciated.

This should help you understand the process better How to Use Pex Go-Nogo Gauge | eHow.com

Thanks.

My crimper did not come with a no-go gauge... just a go.

I think you are safe to follow most of the steps skipping the no-go final step