Have not had this happen before!

[pavogrande]

unless they have a obvious ring or you check them using palmetto's method chuckin' them out will be a big waste of brass --
since they headspace on belt that case - and others - may have been resized too short in previous reloading causing excess stretching --

 

[EMC45]

I made a tool out of coat hanger wire. Annealed an end, sharpened it then bent it at 90 degree angle. Put into case through neck, when it hits the case head drag it up along the interior case wall. If you feel a slight snag, remove the tool, pinch the case neck closed with a pliers and toss it into the scrap bucket.

Yup, did the same thing with a heavy duty paperclip. Flattened the end and bent it at a 90 and used it to check for the inner ring of seperation.

 

[wallacem]

Good answers above. wallacem