primer piercing?

[DonVoigt]

Originally Posted by mrerick

A 9mm cartridge should headspace on the case mouth. If there is enough taper crimp for a round to push through the chamber ridge that stops the cartridge and establishes headspace, the cartridge is defective.

A secondary cause might relate to the length of the entire toggle train and any play caused by wear at any of the axle pins, and where the breech face has been positioned relative to the head of the cartridge. You might also look at the fitting and condition of the extractor.

Marc,
if you read all of GT post, you will see that he is trying to "save" a worn out barrel with almost no chamber left. So in this case it is the barrel not the ammo that is the problem. There is a measurable crimp variation from brand to brand and lot to lot on ammo.

The fact that he has checked the chamber with gages shows that the "stopping" ring at the front is just large enough to catch the sharp edge of the gage, but not the "soft, and tapered edge of some brass.

The extractor does not even enter the equation, it not intended to "hold" the cartridge against the breech face.

GT's problem is clear, least to me it is, JMHO.